GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Dutchie on April 03, 2017, 07:54:48 PM
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Hello everyone,
I recieved my new Crosman 2240 about a week ago and have been shooting it at about 3 meters. I am VERY pleased with the accuracy at this distance, albeit quite short. I can obliterate the bull's eye with 5 shots at 3 meters. I am not going to shoot it at any farther than about 7-8 meters due to space restrictions. I am sure the stock 2240 would do fine at this but I would still like to optimize it to my specific wishes, just for the fun of it. By that I have a few modifictions in mind that I would like to share with you ang get your advice on.
Semi-related to this thread, here's a quick little tip on building a home made, poor man's "silencer" that I have found to be very easy and fairly effective to make this gun more neighbour-friendly. Take a laundry rack, put some blankets and pillows over it, leave a big hole at the back and a smaller hole at the front. Place this contraption in front of you when you shoot, holding the gun inside of it and shooting through the smaller hole in the front. It's a hassle to do this until I install a silencer, but I'd say it cuts the sound level by about 30-50%.
I have quite a long list of questions. Please don't hesitate to respond if you can pitch in on only one, any advice is greatly appreciated.
First a few general questions before I get into the modding part:
1. I am used to shooting air rifles (I have a CZ Slavia 631), and not so much pistols. My left eye is dominant so with rifles I have to close my left eye because it's hard for me to focus on the right eye's image without closing the left. With pistols (my friend's Webley Tempest and my 2240) I have found myself shooting with my left eye instead without closing my right eye. Is this acceptable technique or does it mess up my stance or something?
2. Is it harmful to the gun to cock it and pull the trigger without charging or loading it, as it is harmful to shoot springers without a pellet? I've been assuming it isn't and I've been doing it a lot to practice my trigger pull, but I'm asking just in case.
Now for the modding, a huge part of the reason why I bought this gun.
3. I plan on installing a silencer, will this cause any decreases or increases in velocity and/or accuracy?
4. Does anyone have any experience with both a Weihrauch silencer and a TKO silencer? I am leaning towards the Weihrauch because I am under the impression that it's more quiet, but if the TKO is only very slightly less quiet, I might go for that as it's smaller. I think the TKO slides on instead of screwing on though. If that's the case I probably prefer the Weihrauch or another screw-on silencer as I also want to be able to shoot it without the silencer attached.
5. If I buy the Weihrauch, I plan on installing this adapter:
(https://www.db-schietsport.nl/754-large_default/crosman-2240-12-unf-adapter.jpg)
Will this cause any changes in accuracy if I leave it on without the silencer?
6. As I want to be able to shoot without the silencer attached, I will need front sights on this adapter. I know of one solution, which is to use a longer set screw in the adapter. But preferably I would like to have one of those transparent green sticks as my front sight. There is a metal workshop on my street. I haven't gone in to ask yet, but maybe some of you know more about what kind of equipment a metal workshop typically has. Do you think they would be able to make me something from scratch that I can mount on top of the adapter and place a one of those green sticks in? Would they be able to blue it to match the color of the gun?
7. Internals: I would like to make this gun shoot as fast as possible with a 7.5" barrel without wasting any CO2. As I understand it, the CO2 valve stays open for too long in the stock 2240 which lets out too much gas resulting in wasted CO2 and the notoriously loud pop when firing. I've found three common mods changing the flow of CO2. (1) Changing the hammer spring, (2) installing a power adjuster, (3) changing the angle of the link between the barrel and the CO2 valve to 45 degrees instead of 90. Which of these mods, and/or others, would you recommend for my situation? I've read conflicting reports of the effectiveness of the hammer spring mod and the power adjuster, especially in conjunction with each other. One thing that makes it hard for me to find an answer to this is that most people looking for more power change the length of their barrel, which I don't want to do. I want to keep the gun compact, as it's already going to be quite long with the silencer. I want maximum power and efficiency of CO2 use with a stock barrel, maybe down the line even a shortened one. I have no budget limits for this gun. Not because I'm rich, just because I'm patient and it's fine if it takes years to build.
8. I've read that installing a long steel breech may affect accuracy and even velocity, is this true?
9. I think I've also read that the main tube of the 2250 doesn't have the stamping with the safety cautions on it, and is interchangeable with the 2240. Is this true?
10. I think I've seen kits for 2-stage triggers. Do you think this is worth the effort? Also, I've seen lots of pictures with brass triggers. Exactly the same trigger except in brass. Are these all custom or did Crosman use to make them that way? I'm going to make mine black with brass accents and wooden grips, so a brass trigger would be nice.
11. Does anyone know of some dark colored (preferably slightly reddish) wooden grips, WITH checkering?
12. Does anyone know of a straight-pull bolt system for the 2240? Small thing, but I would rather only have to pull the bolt back rather than up and back, I feel that would suit a pistol better.
13. I'm looking at this rear sight:
(http://i.ebayimg.com/images/g/x-MAAMXQiM5Q~JuJ/s-l300.jpg)
I'm sure many of you know it, it's offered on the custom Crosman webshop. I like the fact that it's rather small compared to the other sights offered by Crosman, and I like the white dots, would especially like that together with the green front sight. Does anyone know of any other similar alternatives which may be better?
Well, that's all I could come up with for now. I know that some answers can be found by using google, and I have already done a LOT of reading even before recieving the pistol in the mail. But I've found myself somewhat lost in the enormous amount of information. I've also noticed that lots of times, changing one thing has an effect on another thing, such as the silencer remocing the front sight or the conjunction between hammer spring mods and power adjusters. That's why I thought it would be good to make a thread specific to my situation to guide me as I customize my 2240. I'm not expecting all of these anwers to be answered very quickly, but I'm very much looking forward to reading your thoughts.
PS: For those interested, here are some of the plans I have for this which I didn't have any questions about. I plan to keep this gun as modular as possible, being able to shoot it as a simple pistol with open sights, or with accesories such as a red dot sight, laser mounted on the trigger guard and a silencer. I want none of these to be required for one another, hence the questions about the front sight on the silencer adapter and the rear sight, even though I will buy a red dot sight as well. I will also use brass caps on the front and back sides of the main tube where you place the CO2 (maybe a power adjuster on the back end, but it would have to be brass), a brass safety pin, brass screws in the grips, the bolt will stay brass but may be changed to a different shape, and maybe a brass barrel band but I don't think so, I think that would probably be too much for brass accents. The trigger will probably be brass as well, maybe with a black trigger shoe, I think that might look good.
Happy shooting!
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It's unlimited on what type of modifications you can do to the 2240. I ended with enough spare parts to assemble 2 more pistols.
The only problem is that you will kick yourself after adding up the cost of all the parts. It world be more economical to start with the 2250 with the steel breech. It's too addictive but a lot of fun. Bob
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wow covered alot of ground. first the 45degree mod is inside of the valve, not to the transfer port. clipping a coil or 2 will make the gun alittle more effiecient and just alittle quieter. the power adjuster could allow you you drop the power back to where you are getting better efficiency. cutting back the flow of co2 alittle may save you co2 and lower the noise while only minimally affect fps. but remember, there's always a trade off. nothing is free. more power, more co2, or longer barrel etc. no free ride.
gmac makes alot of parts, nice brass bits. of intrest to you maybe a brass barrel band with dovetails on the bottom. this allows accesories to be attatched to the bottom. also have wood grips. i know a chinese place with checkered grip also if you dont mind chinese.
trigger, if you want the best possible trigger for this platform in pistol form, get yourself a p-rod trigger group from crosman. not overly expensive and well worth it. uyou'll need a different hammer for this trigger. or mod the original. easy jb weld mod.lol. i go a different route though.
if you want to use that lpa site you'll need a crosman breech with the cross cut 3/8" dove tail. i haven.t seen after market breeches with the cut. maybe gmac. if you go with different rear site gmac makes a nice brass breech. most after market breeches have 2 barrel hold down screws. you could always drill and tap a crosman breeech for an extra one. some after market breeches also come in aluminum, saves some wieght.
front site. if you take off the moderater there are several sites that will go on the barrel .
have fun
kj
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I added the Crosman LPA rear sight and swapped out the front site for a fiber optic site, it makes it much nicer, I just wish the rear LPA had fiber optics also. Of course if your going to add a silencer, you may not be able to use the front sight since it installs the same as the original. Best of luck with your project, I look forward to seeing the finished product.
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A lot of questions at once. Only responding to two.
#2 No harm in doing so. An aside; If loaded or unloaded and cocked, it can be decocked by firmly holding the bolt, pulling the trigger, and slowly bringing the bolt into battery.
#7 A stock 7.5" 2240 is rather wasteful of CO2. Use the Crosman PA assembly from the 2300S - very inexpensive and includes a hammer spring. Consider the internal valve sleeve from the 2300T to reduce valve capacity.
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Maybe this will give you a couple ideas... nothing fancy, just a pile of stuff I put together. Some of the key things making it a bit more efficient are the PA, light hammer spring and the BHB mod (BStaley Hammer O-rings mod)
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Hello everyone,
I recieved my new Crosman 2240 about a week ago and have been shooting it at about 3 meters. I am VERY pleased with the accuracy at this distance, albeit quite short. I can obliterate the bull's eye with 5 shots at 3 meters. I am not going to shoot it at any farther than about 7-8 meters due to space restrictions. I am sure the stock 2240 would do fine at this but I would still like to optimize it to my specific wishes, just for the fun of it. By that I have a few modifictions in mind that I would like to share with you ang get your advice on.
Semi-related to this thread, here's a quick little tip on building a home made, poor man's "silencer" that I have found to be very easy and fairly effective to make this gun more neighbour-friendly. Take a laundry rack, put some blankets and pillows over it, leave a big hole at the back and a smaller hole at the front. Place this contraption in front of you when you shoot, holding the gun inside of it and shooting through the smaller hole in the front. It's a hassle to do this until I install a silencer, but I'd say it cuts the sound level by about 30-50%.
I have quite a long list of questions. Please don't hesitate to respond if you can pitch in on only one, any advice is greatly appreciated.
First a few general questions before I get into the modding part:
1. I am used to shooting air rifles (I have a CZ Slavia 631), and not so much pistols. My left eye is dominant so with rifles I have to close my left eye because it's hard for me to focus on the right eye's image without closing the left. With pistols (my friend's Webley Tempest and my 2240) I have found myself shooting with my left eye instead without closing my right eye. Is this acceptable technique or does it mess up my stance or something?
2. Is it harmful to the gun to cock it and pull the trigger without charging or loading it, as it is harmful to shoot springers without a pellet? I've been assuming it isn't and I've been doing it a lot to practice my trigger pull, but I'm asking just in case.
Now for the modding, a huge part of the reason why I bought this gun.
3. I plan on installing a silencer, will this cause any decreases or increases in velocity and/or accuracy?
4. Does anyone have any experience with both a Weihrauch silencer and a TKO silencer? I am leaning towards the Weihrauch because I am under the impression that it's more quiet, but if the TKO is only very slightly less quiet, I might go for that as it's smaller. I think the TKO slides on instead of screwing on though. If that's the case I probably prefer the Weihrauch or another screw-on silencer as I also want to be able to shoot it without the silencer attached.
5. If I buy the Weihrauch, I plan on installing this adapter:
(https://www.db-schietsport.nl/754-large_default/crosman-2240-12-unf-adapter.jpg)
Will this cause any changes in accuracy if I leave it on without the silencer?
6. As I want to be able to shoot without the silencer attached, I will need front sights on this adapter. I know of one solution, which is to use a longer set screw in the adapter. But preferably I would like to have one of those transparent green sticks as my front sight. There is a metal workshop on my street. I haven't gone in to ask yet, but maybe some of you know more about what kind of equipment a metal workshop typically has. Do you think they would be able to make me something from scratch that I can mount on top of the adapter and place a one of those green sticks in? Would they be able to blue it to match the color of the gun?
7. Internals: I would like to make this gun shoot as fast as possible with a 7.5" barrel without wasting any CO2. As I understand it, the CO2 valve stays open for too long in the stock 2240 which lets out too much gas resulting in wasted CO2 and the notoriously loud pop when firing. I've found three common mods changing the flow of CO2. (1) Changing the hammer spring, (2) installing a power adjuster, (3) changing the angle of the link between the barrel and the CO2 valve to 45 degrees instead of 90. Which of these mods, and/or others, would you recommend for my situation? I've read conflicting reports of the effectiveness of the hammer spring mod and the power adjuster, especially in conjunction with each other. One thing that makes it hard for me to find an answer to this is that most people looking for more power change the length of their barrel, which I don't want to do. I want to keep the gun compact, as it's already going to be quite long with the silencer. I want maximum power and efficiency of CO2 use with a stock barrel, maybe down the line even a shortened one. I have no budget limits for this gun. Not because I'm rich, just because I'm patient and it's fine if it takes years to build.
8. I've read that installing a long steel breech may affect accuracy and even velocity, is this true?
9. I think I've also read that the main tube of the 2250 doesn't have the stamping with the safety cautions on it, and is interchangeable with the 2240. Is this true?
10. I think I've seen kits for 2-stage triggers. Do you think this is worth the effort? Also, I've seen lots of pictures with brass triggers. Exactly the same trigger except in brass. Are these all custom or did Crosman use to make them that way? I'm going to make mine black with brass accents and wooden grips, so a brass trigger would be nice.
11. Does anyone know of some dark colored (preferably slightly reddish) wooden grips, WITH checkering?
12. Does anyone know of a straight-pull bolt system for the 2240? Small thing, but I would rather only have to pull the bolt back rather than up and back, I feel that would suit a pistol better.
13. I'm looking at this rear sight:
(http://i.ebayimg.com/images/g/x-MAAMXQiM5Q~JuJ/s-l300.jpg)
I'm sure many of you know it, it's offered on the custom Crosman webshop. I like the fact that it's rather small compared to the other sights offered by Crosman, and I like the white dots, would especially like that together with the green front sight. Does anyone know of any other similar alternatives which may be better?
Well, that's all I could come up with for now. I know that some answers can be found by using google, and I have already done a LOT of reading even before recieving the pistol in the mail. But I've found myself somewhat lost in the enormous amount of information. I've also noticed that lots of times, changing one thing has an effect on another thing, such as the silencer remocing the front sight or the conjunction between hammer spring mods and power adjusters. That's why I thought it would be good to make a thread specific to my situation to guide me as I customize my 2240. I'm not expecting all of these anwers to be answered very quickly, but I'm very much looking forward to reading your thoughts.
PS: For those interested, here are some of the plans I have for this which I didn't have any questions about. I plan to keep this gun as modular as possible, being able to shoot it as a simple pistol with open sights, or with accesories such as a red dot sight, laser mounted on the trigger guard and a silencer. I want none of these to be required for one another, hence the questions about the front sight on the silencer adapter and the rear sight, even though I will buy a red dot sight as well. I will also use brass caps on the front and back sides of the main tube where you place the CO2 (maybe a power adjuster on the back end, but it would have to be brass), a brass safety pin, brass screws in the grips, the bolt will stay brass but may be changed to a different shape, and maybe a brass barrel band but I don't think so, I think that would probably be too much for brass accents. The trigger will probably be brass as well, maybe with a black trigger shoe, I think that might look good.
Happy shooting!
On the performance increase side..Get a striker spring adjuster, a Pro-Top, Disco valve body and stem (to go with the Pro-Top) lighten the striker and groove the bottom to be sure it it clears the sear, use an ice maker tube transfer port with a metal breech and an bolt with an extended probe.
Here's a link to a 6" barreled 2240 build that I did a while back, along with some chrony results. ( If this link is not permissible mod please delete, and my apologies)
http://www.network54.com/Forum/275684/message/1304372593/Birthday+Girl%27s+2240 (http://www.network54.com/Forum/275684/message/1304372593/Birthday+Girl%27s+2240)
http://www.network54.com/Forum/275684/message/1307143098/Got+to+shoot+Birthday+Girls+2240 (http://www.network54.com/Forum/275684/message/1307143098/Got+to+shoot+Birthday+Girls+2240)
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If you think you can get much more performance from a 2240 with stock 7.5" barrel, you will be disappointed.... You can make it bark louder, and burn through more CO2.... but the short barrel is going to put an upper limit on your power.... Shooting at higher temperatures will help, because the higher gas pressure will give the pellet more of an initial kick.... but changing out the hammer spring, or increasing the preload, just wastes even more gas than the gun does already....
On the other hand, if you want to get a lot more shots, at a more constant velocity (not dropping as fast as the gun cools during shooting).... you can REDUCE the hammer spring preload, or shorten the spring.... You can also lighten the hammer.... and you can, of course, fit an SSG.... It is easy to double the number of shots without having less velocity than you would at the end of a normal 30 shot string on a stock gun....
The choice is yours.... loud and gas hungry.... or a sweet, much quieter (even without a can), and way more economical shooter....
Bob
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It's unlimited on what type of modifications you can do to the 2240. I ended with enough spare parts to assemble 2 more pistols.
The only problem is that you will kick yourself after adding up the cost of all the parts. It world be more economical to start with the 2250 with the steel breech. It's too addictive but a lot of fun. Bob
I had considered that too, but I'm not really the kind of person that saves up to buy all the good stuff at once. I chose to just buy the 2240 so I could get started and just already have fun shooting it. Finished my tin of 250 pellets today a week after buying it. I'll add upgrades every month probably. Might not be the most efficient way of doing it, but it was the most instantly gratifying way and I'm a millenial. ;D
wow covered alot of ground. first the 45degree mod is inside of the valve, not to the transfer port. clipping a coil or 2 will make the gun alittle more effiecient and just alittle quieter. the power adjuster could allow you you drop the power back to where you are getting better efficiency. cutting back the flow of co2 alittle may save you co2 and lower the noise while only minimally affect fps. but remember, there's always a trade off. nothing is free. more power, more co2, or longer barrel etc. no free ride.
gmac makes alot of parts, nice brass bits. of intrest to you maybe a brass barrel band with dovetails on the bottom. this allows accesories to be attatched to the bottom. also have wood grips. i know a chinese place with checkered grip also if you dont mind chinese.
trigger, if you want the best possible trigger for this platform in pistol form, get yourself a p-rod trigger group from crosman. not overly expensive and well worth it. uyou'll need a different hammer for this trigger. or mod the original. easy jb weld mod.lol. i go a different route though.
if you want to use that lpa site you'll need a crosman breech with the cross cut 3/8" dove tail. i haven.t seen after market breeches with the cut. maybe gmac. if you go with different rear site gmac makes a nice brass breech. most after market breeches have 2 barrel hold down screws. you could always drill and tap a crosman breeech for an extra one. some after market breeches also come in aluminum, saves some wieght.
front site. if you take off the moderater there are several sites that will go on the barrel .
have fun
kj
Would you recommend to both lighten the hammer spring and install a power adjuster?
I've found gmac and you're right, they make very nice stuff. I was thinking to get the steel breech from there, but I want a black one rather than a brass one. Does anyone have experience with the black one? Does it come with dovetails to mount Crosman's LPA sights? I will probably need something like the barrel band to mount accesories on the bottom, thanks for that tip. And I don't mind ordering from China, I have plenty of time. Do you happen to have a link?
As for the trigger, I looked up the P-Rod and it looks pretty great! Apperantly it's a 2 stage trigger with both stages being adjustable, that is new to me. So the different hammer, how different is it and can you buy it? I don't know what a jb weld is but I can probably do some basic welding at the car garage. What did you do with yours?
I had assumed that all after market breeches have a dove tail cut into them, as they're often mentioned as a necessity for mounting optics like red dots or scopes? And why the suggestion of drilling and tapping an extra hole in the Crosman breech? I don't quite understand what thats's for.
The front sight, I am planning to leave the adapter for the moderator on when not using the moderator. That's why I need a front sight on top of the adapter. I just think it's a little cooler to be able to just screw on/off the moderator and be able to use the gun, rather than also having to reinstall the front sights.
I added the Crosman LPA rear sight and swapped out the front site for a fiber optic site, it makes it much nicer, I just wish the rear LPA had fiber optics also. Of course if your going to add a silencer, you may not be able to use the front sight since it installs the same as the original. Best of luck with your project, I look forward to seeing the finished product.
I think I would like the white dots rear sights with fibre optics front sights front sights combination. Seems extra fancy to me somehow to have different rear and front sights. ;D
I think my best bet now would be to buy the fibre optic front sight, cut it off, and glue it on top of my moderator thread adapter.
A lot of questions at once. Only responding to two.
#2 No harm in doing so. An aside; If loaded or unloaded and cocked, it can be decocked by firmly holding the bolt, pulling the trigger, and slowly bringing the bolt into battery.
#7 A stock 7.5" 2240 is rather wasteful of CO2. Use the Crosman PA assembly from the 2300S - very inexpensive and includes a hammer spring. Consider the internal valve sleeve from the 2300T to reduce valve capacity.
I think it's great that I can practice my trigger pull without using any CO2. I've probably dry fired this gun more than I've fired it. ;D
PA assembly is a power adjuster? I didn't know Crosman makes them. What does this do for me? Would it allow me to adjust the hammer spring so that it's just allowing CO2 to escape until the pellet leaves the barrel, and no longer? That's my current understanding of how power adjusters and hammer spring mods work, but I'm not sure I understood that right. What is a valve sleeve and why do I want to reduce valve capacity?
Maybe this will give you a couple ideas... nothing fancy, just a pile of stuff I put together. Some of the key things making it a bit more efficient are the PA, light hammer spring and the BHB mod (BStaley Hammer O-rings mod)
I love how compact you've made it! I looks very nice how you've managed to keep the end of the barrel flush with the end cap of the main tube. Do you happen to know how fast it shoots? And what have you mounted on the end of the barrel?
So a lighter hammer spring makes the valve stay open shorter, thus decreasing the amount of CO2 escaping during a shot? And what does a BHB mod do? Never heard of this, getting some great new information here.
On the performance increase side..Get a striker spring adjuster, a Pro-Top, Disco valve body and stem (to go with the Pro-Top) lighten the striker and groove the bottom to be sure it it clears the sear, use an ice maker tube transfer port with a metal breech and an bolt with an extended probe.
Here's a link to a 6" barreled 2240 build that I did a while back, along with some chrony results. ( If this link is not permissible mod please delete, and my apologies)
[Had to remove your links in the quote because it wouldn't allow me to post otherwise]
Wow, quite a bit more is possible than I had found while reading before. I'm a little bit lost as most of these terms are unfamiliar to me. If it's not too much to ask, could you maybe elaborate more on some of this and what it does? I don't know what these things are: striker spring, is this the same as the hammer spring, and so the same thing that's sometimes referred to as a power adjuster? I also don't know what a Pro-Top is. Is a sear the part of the trigger assembly that moves down to release the hammer? And what's an ice maker tube transfer port? The extended probe I understand what it means, but I'm not sure what it does. I've also heard of a hollow probe but I've seen some people say they're useless and I also don't quite understand what their for. What are your thoughts?
Very nice little gun! I love the more compact 2240's. And that shot string was unexpected. It seems to shoot faster than out of the box. I think I'm missing some part of my comprehension about how all of this works. From what I've been reading in some of the replies, I got the impression that the stock 2240 lets out too much CO2 during every shot for the length of the barrel. What I inferred from that is that all you can do with a short barrel is to increase efficiency and not power. So how have you managed to increase the velocity even with a shorter barrel?
If you think you can get much more performance from a 2240 with stock 7.5" barrel, you will be disappointed.... You can make it bark louder, and burn through more CO2.... but the short barrel is going to put an upper limit on your power.... Shooting at higher temperatures will help, because the higher gas pressure will give the pellet more of an initial kick.... but changing out the hammer spring, or increasing the preload, just wastes even more gas than the gun does already....
On the other hand, if you want to get a lot more shots, at a more constant velocity (not dropping as fast as the gun cools during shooting).... you can REDUCE the hammer spring preload, or shorten the spring.... You can also lighten the hammer.... and you can, of course, fit an SSG.... It is easy to double the number of shots without having less velocity than you would at the end of a normal 30 shot string on a stock gun....
The choice is yours.... loud and gas hungry.... or a sweet, much quieter (even without a can), and way more economical shooter....
Bob
I know there's an upper limit to velocity with a short barrel. I don't want a loud barking, gas wasting, inefficient and not even more powerful gun. Doubling the amount of shots is already a great improvement of course and I would be very happy with it. But if it's also possible to gain some power while also increasing efficiency, that would of course be even better. I don't want extra power so badly that I'm willing to mount a longer barrel, but any power increase that can be achieved with a stock barrel would be very welcome. Maybe something like the 45 degree mod in the valve could let more CO2 into the barrel faster, while still closing the valve again before the pellet has left the barrel and thus any more CO2 is waste. Or am I understanding the whole process wrong?
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I am not aware of any way to angle the exhaust port in the gun 45 degrees.... even 30* would be questionable.... I mod. my Disco valves with a 5/32" end mill, plunged in at an angle of 20*, and then round the bottom end, where it joins the throat of the valve, with a small Dremel burr.... That is about all you can do, and I don't really think you will gain very much on CO2 with a short barrel.... I am doing those mods. on a rifle with a 24" barrel at 2000 psi air pressure, and it is worthwhile then.... It likely won't hurt on a 2240 in .22 cal, but porting in that manner would be too big for a .177.... You can drill out the transfer port to as large as 0.162", and the barrel port the same size, but again you may not gain, but in .22 cal are unlikely to lose.... Making port mods without backing off on the hammer spring will make the gun use even more CO2, with very little velocity gain because of the short barrel.... If you reduce the hammer spring preload, and/or shorten the spring, to save CO2, you may end up with close to the power you have now, and more shots....
Don't expect too much.... and enjoy the journey.... ;)
Bob
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ok, yes most, if not all the breeches have dovetails cut for optics. for the lpa site there needs to be a 3/8" dovetail cut perpendicular to the breech for the site to fit in. alot of other options for rear sights without that, that will fit the normal dovetails.
jb weld is a metal epoxy that some use to fill in the waist on the hammer to make it work with the p-rod trigger group. mellonair makes one that works without having to use jb weld. i use the p-rod hammer/striker/ acetal pin and p-rod end cap. i use this set-up cuz i can then adjust the hammer pre-load(like a power adjuster) and i can adjust the throw as well. something you can't do with other hammer and power adjuster set-ups.
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I am not aware of any way to angle the exhaust port in the gun 45 degrees.... even 30* would be questionable.... I mod. my Disco valves with a 5/32" end mill, plunged in at an angle of 20*, and then round the bottom end, where it joins the throat of the valve, with a small Dremel burr.... That is about all you can do, and I don't really think you will gain very much on CO2 with a short barrel.... I am doing those mods. on a rifle with a 24" barrel at 2000 psi air pressure, and it is worthwhile then.... It likely won't hurt on a 2240 in .22 cal, but porting in that manner would be too big for a .177.... You can drill out the transfer port to as large as 0.162", and the barrel port the same size, but again you may not gain, but in .22 cal are unlikely to lose.... Making port mods without backing off on the hammer spring will make the gun use even more CO2, with very little velocity gain because of the short barrel.... If you reduce the hammer spring preload, and/or shorten the spring, to save CO2, you may end up with close to the power you have now, and more shots....
Don't expect too much.... and enjoy the journey.... ;)
Bob
I think this is starting to make sense to me. So correct me if I'm wrong, what you're saying is that I can widen the channels through which the CO2 passes, and angle them a little more smoothly. This way more CO2 can flow out of the valve during the time it's open. Then if I can combine that with a lighter hammer spring, the valve stays open for slightly shorter but because of the widening/angles of the CO2 channels, more CO2 will come out during that time before the pellet leaves the barrel, thus reducing CO2 waste. Correct? Also, what's a disco valve?
I'm not expecting much, I'm well aware of the limits with a stock barrel. But I'm still interested in making it as powerful and efficient as it can possibly be with that barrel.
ok, yes most, if not all the breeches have dovetails cut for optics. for the lpa site there needs to be a 3/8" dovetail cut perpendicular to the breech for the site to fit in. alot of other options for rear sights without that, that will fit the normal dovetails.
jb weld is a metal epoxy that some use to fill in the waist on the hammer to make it work with the p-rod trigger group. mellonair makes one that works without having to use jb weld. i use the p-rod hammer/striker/ acetal pin and p-rod end cap. i use this set-up cuz i can then adjust the hammer pre-load(like a power adjuster) and i can adjust the throw as well. something you can't do with other hammer and power adjuster set-ups.
Does the Crosman steel breech have the perpendicular 3/8" dovetail for mounting the LPA sights? Weird that these sights require a dovetail perpendicular to the breech rather than just fitting on a normal one parallel to it. And what are some of the things to look for in buying a good breech? I've seen them available from multiple sources but it's hard to tell if and how they're any different from one another. I'd rather not have to go to the metal workshop and have them cut covetails, as that would mean the blueing from that part is gone.
I thought striker and hammer were the same thing. The JB weld sounds very simple, that sounds like it would be worth it not having to order a modified hammer from mellonair. Also, what's an acetal pin?
Edit: Looking at the picture of the LPA sights in my original post, it looks to me like they're sitting on normal parallel dovetails? I think I don't quite understand what you mean.
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if you look at the pic of the lpa site you posted , look at the bottom, that is a 3/8" dovetail that is cut perpendicular to the scope rails. here's some pics i took...in the pics with 3 breeches , the middle one is the type that accepts the lps site. the top type has the rear cut to accept the original plastic site, the bottom siver/aluminum has niether. if you can't tell from pics on vendors website if the breech will accept the lpa site, ask them . breeches from crosman also come in a short type that i don't have. never had a desire for less room for mounting optics. i prefer the flat sided type breech, like the silver/aluminum breech for asthetic reasons. i had a dozen special made in aluminum and afew in brass. had the aluminum ones anodized in blue, black and natural. the blue ones i also had engraved. as long as you can mount the optics you like , choice in available breeches is a matter of taste. the crosman ones are the only ones i know of that have the perpendicular dovetail for the lpa site. down side is they only have 1 barrel hold down screw. though an extra one can easily be added.
(http://i1281.photobucket.com/albums/a505/bbb151/003_zpswecfldmp.jpg) (http://s1281.photobucket.com/user/bbb151/media/003_zpswecfldmp.jpg.html)
(http://i1281.photobucket.com/albums/a505/bbb151/002_zpsabdcykvu.jpg) (http://s1281.photobucket.com/user/bbb151/media/002_zpsabdcykvu.jpg.html)
(http://i1281.photobucket.com/albums/a505/bbb151/004_zpsfcnwz9u1.jpg) (http://s1281.photobucket.com/user/bbb151/media/004_zpsfcnwz9u1.jpg.html)
(http://i1281.photobucket.com/albums/a505/bbb151/001_zpsg3xypvpg.jpg) (http://s1281.photobucket.com/user/bbb151/media/001_zpsg3xypvpg.jpg.html)
(http://i1281.photobucket.com/albums/a505/bbb151/007_zpsai66otj7.jpg) (http://s1281.photobucket.com/user/bbb151/media/007_zpsai66otj7.jpg.html)
(http://i1281.photobucket.com/albums/a505/bbb151/009_zpsjtfkvfq5.jpg) (http://s1281.photobucket.com/user/bbb151/media/009_zpsjtfkvfq5.jpg.html)
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Disco valve = from a Crosman/Benjamin Discovery PCP rifle.... It is the same basic valve as a 22XX valve, with an extended front end, sealed into the tube with O-rings.... Internally, the dimensions are the same as a 22XX valve, but it has a harder poppet to withstand the higher pressures.... I am not suggesting it for your use, there would be no advantage, I just mentioned it because the porting is the same, and the same modifications would apply....
Yes, the idea is to get a smoother, slightly increased gas flow, and then shorten the valve dwell to conserve CO2.... The first part of the impulse does more of the work of accelerating the pellet, and there is no point in keeping the valve open after the pellet leaves the muzzle, of course.... A stock 2240 does exactly that, you can reduce the hammer spring preload and save CO2 without losing any velocity initially....
Here is what happens with a 2240 with a 14" barrel as you change the hammer spring preload.... The 7.5" barrel will benefit less, if at all, from increased preload.... and note it only effects the first few shots anyways, when there is some liquid CO2 getting into the valve (very wasteful) and before the gun cools.... Shots are about 30 seconds apart....
(http://i378.photobucket.com/albums/oo221/rsterne/1750%20with%20DPH/2240ShotCount_zps353ade53.jpg) (http://s378.photobucket.com/user/rsterne/media/1750%20with%20DPH/2240ShotCount_zps353ade53.jpg.html)
and here is what happens with a 24" barrel showing what you can achieve by tuning to conserve CO2....
(http://i378.photobucket.com/albums/oo221/rsterne/1750%20with%20DPH/2260%20Shot%20Count_zps4gkjbbxf.jpg) (http://s378.photobucket.com/user/rsterne/media/1750%20with%20DPH/2260%20Shot%20Count_zps4gkjbbxf.jpg.html)
Sorry, I don't have similar charts for a 2240 with 7.5" barrel, but you get the idea....
Bob
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striker hammer are generally the same thing, the difference here is that the p=rod one is 3 pieces, hammer, striker/acetal pin. the acetal pin is just a small piece of nylon that locks the striker from moving on its' own....
(http://i1281.photobucket.com/albums/a505/bbb151/015_zpsmdh2aqlx.jpg) (http://s1281.photobucket.com/user/bbb151/media/015_zpsmdh2aqlx.jpg.html)
(http://i1281.photobucket.com/albums/a505/bbb151/011_zpsu52j77b3.jpg) (http://s1281.photobucket.com/user/bbb151/media/011_zpsu52j77b3.jpg.html)
the striker is threaded into the hammer and can be adjusted for throw from outside the gun if using the p=rod end cap, which is also 2 pieces and needs one hole drilled and tapped to fit your gun. then the pre-load can also be adjusted.
the crosman website has a section with all the manuals with exploded parts diagrams. you'll need to get familiar with that so you can get parts numbers for ordering. you need them to order, customer service isn't going to look up all the parts for you..lol
peace
kj
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dutch, you also do well to look up some of bobs' , rsterne , past posts on co2, lots of excellent info there for sure, i've leaned alot from him over the years.
fivestar, anthony is also a wealth of info for sure. he produces the pro top. using the protop allows removal of the piercing pin and gives a straighter co2 flow path. worth considering.
hats off to bob and anthony
peace
kj
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I love how compact you've made it! I looks very nice how you've managed to keep the end of the barrel flush with the end cap of the main tube. Do you happen to know how fast it shoots? And what have you mounted on the end of the barrel?
So a lighter hammer spring makes the valve stay open shorter, thus decreasing the amount of CO2 escaping during a shot? And what does a BHB mod do? Never heard of this, getting some great new information here.
Sorry for the delay in responding.
I just took a stock 2240 barrel and measured it for the barrel band and muzzle brake to get my length and chopped it off then recrowned it. I wasn't going for shot count or power... it was pure "cool". I wanted a stubby and had a bunch of stuff laying around. I must be honest, I did steal a couple parts from Betty Lou's 2260 HPA carbine that the mailman just delivered replacements for today. I think I get 35 or so shots from a C02 and waste a ton of it. The muzzle brake is from a 2260 I think? I've never chronied it so all I can tell you is that anything within 20 meters gets hammered. And those .22 benji destroyers turn into shrapnel. The BHB and shorter hammer spring all but eliminates hammer bounce and possibly flattens the string out some. The power adjuster allows me to have a little more control on shot count. I begin a C02 cart with it backed out the slowly turn it in throughout the shot string until I completely lose POI. I usually end up dry firing 6 - 8 times to empty the remains of the C02 cart for replacing. It's just a fun gun to have in the fishing box or in the glovebox/under the seat. Sometimes we are in our barn/bar/shop/indoor shooting range late in the evening with our scoped plinkers. Various night creatures visit uninvited. Willie G. Stubbs is a great guy to have laying in wait on the shooting bench.
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if you look at the pic of the lpa site you posted , look at the bottom, that is a 3/8" dovetail that is cut perpendicular to the scope rails. here's some pics i took...in the pics with 3 breeches , the middle one is the type that accepts the lps site. the top type has the rear cut to accept the original plastic site, the bottom siver/aluminum has niether. if you can't tell from pics on vendors website if the breech will accept the lpa site, ask them . breeches from crosman also come in a short type that i don't have. never had a desire for less room for mounting optics. i prefer the flat sided type breech, like the silver/aluminum breech for asthetic reasons. i had a dozen special made in aluminum and afew in brass. had the aluminum ones anodized in blue, black and natural. the blue ones i also had engraved. as long as you can mount the optics you like , choice in available breeches is a matter of taste. the crosman ones are the only ones i know of that have the perpendicular dovetail for the lpa site. down side is they only have 1 barrel hold down screw. though an extra one can easily be added.
Ah, the old "we'll sell you this but it only works with this other product of ours" trick. No worries. Do you know of any sights that are similar to the LPA that will fit on a standard dovetail? If not I guess I'll buy the Crosman breech and have an extra hole with threading made like you suggested. I do also like the shape of your aluminium one though. How does the black anodization match up to the blueing (I think it's blueing) on the stock barrel and main tube? Is it the top one in your picture? And what does it mean to anodize something in "natural"? What color does it come out as?
Also, you say you had a dozen special made, how do you mean? Specially made to your specifications? Where did you have this done? Related to my question 6 in my original post. There's a metal workshop on my street, do you think they'll have the equipment there to make something like that for me? I've looked through the window and I saw that they did have the (don't know what it's called in English) horizontal drill machine. What kind of equipment is needed to make stuff like this?
Disco valve = from a Crosman/Benjamin Discovery PCP rifle.... It is the same basic valve as a 22XX valve, with an extended front end, sealed into the tube with O-rings.... Internally, the dimensions are the same as a 22XX valve, but it has a harder poppet to withstand the higher pressures.... I am not suggesting it for your use, there would be no advantage, I just mentioned it because the porting is the same, and the same modifications would apply....
Yes, the idea is to get a smoother, slightly increased gas flow, and then shorten the valve dwell to conserve CO2.... The first part of the impulse does more of the work of accelerating the pellet, and there is no point in keeping the valve open after the pellet leaves the muzzle, of course.... A stock 2240 does exactly that, you can reduce the hammer spring preload and save CO2 without losing any velocity initially....
Here is what happens with a 2240 with a 14" barrel as you change the hammer spring preload.... The 7.5" barrel will benefit less, if at all, from increased preload.... and note it only effects the first few shots anyways, when there is some liquid CO2 getting into the valve (very wasteful) and before the gun cools.... Shots are about 30 seconds apart....
and here is what happens with a 24" barrel showing what you can achieve by tuning to conserve CO2....
Sorry, I don't have similar charts for a 2240 with 7.5" barrel, but you get the idea....
Bob
Ah, got it on the Disco valve. The thing is, Fivestar and kj recommend a pro-top, and fivestar mentioned I should get a Disco valve to go with it. So is the pro-top a modified hammer/striker? Does that mean it can't go with the p-rod trigger as that would require a p-rod hammer/striker that kj posted?
The red line in the lower chart is amazingly flat! What does SSG stand for?
striker hammer are generally the same thing, the difference here is that the p=rod one is 3 pieces, hammer, striker/acetal pin. the acetal pin is just a small piece of nylon that locks the striker from moving on its' own....
the striker is threaded into the hammer and can be adjusted for throw from outside the gun if using the p=rod end cap, which is also 2 pieces and needs one hole drilled and tapped to fit your gun. then the pre-load can also be adjusted.
the crosman website has a section with all the manuals with exploded parts diagrams. you'll need to get familiar with that so you can get parts numbers for ordering. you need them to order, customer service isn't going to look up all the parts for you..lol
peace
kj
I'm not sure I quite understand what this is for. What do you mean by "throw", which you said can be adjusted? I think what I'm getting from this is that you can screw the striker deeper into the hammer, so that it's shorter, in order to decrease the amount of time it leaves the valve open. Am I right? It also looks a bit lighter than the stock hammer, does it make any difference in vibrations when firing?
dutch, you also do well to look up some of bobs' , rsterne , past posts on co2, lots of excellent info there for sure, i've leaned alot from him over the years.
fivestar, anthony is also a wealth of info for sure. he produces the pro top. using the protop allows removal of the piercing pin and gives a straighter co2 flow path. worth considering.
hats off to bob and anthony
peace
kj
Awesome to see both of them so willing to advice me. Anything in particular that I can read that you think would be comprehensible for me with my current level of understanding?
Sorry for the delay in responding.
I just took a stock 2240 barrel and measured it for the barrel band and muzzle brake to get my length and chopped it off then recrowned it. I wasn't going for shot count or power... it was pure "cool". I wanted a stubby and had a bunch of stuff laying around. I must be honest, I did steal a couple parts from Betty Lou's 2260 HPA carbine that the mailman just delivered replacements for today. I think I get 35 or so shots from a C02 and waste a ton of it. The muzzle brake is from a 2260 I think? I've never chronied it so all I can tell you is that anything within 20 meters gets hammered. And those .22 benji destroyers turn into shrapnel. The BHB and shorter hammer spring all but eliminates hammer bounce and possibly flattens the string out some. The power adjuster allows me to have a little more control on shot count. I begin a C02 cart with it backed out the slowly turn it in throughout the shot string until I completely lose POI. I usually end up dry firing 6 - 8 times to empty the remains of the C02 cart for replacing. It's just a fun gun to have in the fishing box or in the glovebox/under the seat. Sometimes we are in our barn/bar/shop/indoor shooting range late in the evening with our scoped plinkers. Various night creatures visit uninvited. Willie G. Stubbs is a great guy to have laying in wait on the shooting bench.
No worries, I don't have time to be on here checking for replies all the time either, but it's ok if this thread moves slowly. I don't have money to buy all the parts at once anyway.
You've certainly achieved the cool factor on that gun. It's illegal to use an airgun in public places here and you can't carry it on you in such a way that it's within easy reach. Otherwise I probably would have made it like yours as well, carry it to the beach and shoot some cans there.
Can you fill me in a bit on the BHB mod? I think I understood that they are hammer O-rings, and they're supposed to reduce hammer bounce? What exactly is the negative effect of hammer bounce?
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PA assembly is a power adjuster? I didn't know Crosman makes them. What does this do for me? Would it allow me to adjust the hammer spring so that it's just allowing CO2 to escape until the pellet leaves the barrel, and no longer? That's my current understanding of how power adjusters and hammer spring mods work, but I'm not sure I understood that right. What is a valve sleeve and why do I want to reduce valve capacity?
Yes Crosman PA from 2300S - part number 2300-124 - Includes 6 parts including the spring. It allow varying the force applied to the hammer and so the exhaust valve stem.
Go to:
https://support.crosman.com/hc/en-us/articles/203544730-2300S-Owner-s-Manual-EVP-2007-Present-
and open the EVP (exploded view of parts)
The valve sleeve limits the volume inside the valve - part number 2300-037 - actually called spacer but looks like a sleeve.
Go to:
https://support.crosman.com/hc/en-us/articles/203544160-2300T-Owner-s-Manual-EVP-2006-Current-
and open the EVP 9exploded view of parts)
Also reread the post by rsterne; noise and excess CO2 use or efficiency and quieter.
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Can you fill me in a bit on the BHB mod? I think I understood that they are hammer O-rings, and they're supposed to reduce hammer bounce? What exactly is the negative effect of hammer bounce?
Hammer bounce is the effect of the hammer being uncontrolled. You cock the gun then release the trigger to send the hammer into the valve pin to open the exhaust port. The gas is sent up thru the transfer post and send the pellet on it's way. Once the valve is empty the exhaust valve closes to recharge the valve. This can send the hammer back into the hammer spring which send it back forward hitting the valve pin again momentarily discharging wasted gas, albeit with less force. Sounds like the gun is burping. before they began making things like the SSG and TSS the best way to control the hammer (also cheapest even today) is to build up o-rings between the hammer and valve body thereby controlling the hammer from restriking the valve pin.
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PA assembly is a power adjuster? I didn't know Crosman makes them. What does this do for me? Would it allow me to adjust the hammer spring so that it's just allowing CO2 to escape until the pellet leaves the barrel, and no longer? That's my current understanding of how power adjusters and hammer spring mods work, but I'm not sure I understood that right. What is a valve sleeve and why do I want to reduce valve capacity?
Yes Crosman PA from 2300S - part number 2300-124 - Includes 6 parts including the spring. It allow varying the force applied to the hammer and so the exhaust valve stem.
Go to:
[had to remove link]
and open the EVP (exploded view of parts)
The valve sleeve limits the volume inside the valve - part number 2300-037 - actually called spacer but looks like a sleeve.
Go to:
[had to remove link]
and open the EVP 9exploded view of parts)
Also reread the post by rsterne; noise and excess CO2 use or efficiency and quieter.
The Crosman PA is actually quite nice looking, fairly compact. If I'm going with a power adjuster I would like one that doesn't stick out too far in the back.
As for the spacer, does it essentially achieve the same thing as a lighter hammer spring? I mean in the sense that the amount of CO2 that ultimately makes its way to the barrel is reduced? Do you think you can implement both of these without reducing the flow of CO2 too much? I would love more efficiency, but not to the point where it's giving me a lot less power than is possible with this barrel. I suppose the sweet spot is where the valve stays open just long enough to make the pellet reach the maximum velocity possible with this barrel, and no longer and also no shorter.
And if the choice is between noise and excess CO2 use or efficiency and quieter, I would obviously prefer the latter. A 10 shot or so improvement per CO2 capsule would be a nice result I think, don't know if that's achieveable.
So if I understand correctly, the only thing I can do to potentially get a (tiny) increase in power without a longer barrel is to widen some of the channels that the CO2 passes through and angle them more smoothly? Or is there more that can be done?
Can you fill me in a bit on the BHB mod? I think I understood that they are hammer O-rings, and they're supposed to reduce hammer bounce? What exactly is the negative effect of hammer bounce?
Hammer bounce is the effect of the hammer being uncontrolled. You cock the gun then release the trigger to send the hammer into the valve pin to open the exhaust port. The gas is sent up thru the transfer post and send the pellet on it's way. Once the valve is empty the exhaust valve closes to recharge the valve. This can send the hammer back into the hammer spring which send it back forward hitting the valve pin again momentarily discharging wasted gas, albeit with less force. Sounds like the gun is burping. before they began making things like the SSG and TSS the best way to control the hammer (also cheapest even today) is to build up o-rings between the hammer and valve body thereby controlling the hammer from restriking the valve pin.
Wow, the community for custom 2240's has thought of everything! Do you have any idea how much gas is wasted this way/how many shots can be gained with this? The o-rings between the hammer and valve body does seem like a very cheap and easy option indeed. What exactly is an SSG or a TSS?
Also, is the CO2 capsule closed off by the piercing thing when the valve is open?
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Bob Sterne is the only guy I know that has that special calculator to figure that out.
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this gmac breach will fit the lpa site
http://www.gmaccustomparts.com/epages/BT3197.sf/en_GB/?ObjectPath=/Shops/BT3197/Products/001-0501 (http://www.gmaccustomparts.com/epages/BT3197.sf/en_GB/?ObjectPath=/Shops/BT3197/Products/001-0501)
http://www.gmaccustomparts.com/epages/BT3197.sf/en_GB/?ObjectPath=/Shops/BT3197/Products/001-0009 (http://www.gmaccustomparts.com/epages/BT3197.sf/en_GB/?ObjectPath=/Shops/BT3197/Products/001-0009)
about hammer /striker. yes the striker screws in and out of the hammer. the throw is the distance in which the hammer/striker travels to hit the valve stem. the further out the striker the shorter the throw, the shorter the throw, the less power, the less co2 is released by the valve. the hammer is drilled all the way through . when using the p-rod endcap one can stick a long allen wrench in and change the throw without didassembly of the gun. the p-rod end cap also has a spring guide the will screw in and out and can be reached through the back of the p-rod end cap. this part works like a power adjuster by increasing or decreasing hammer spring preload/tension.
the top breech is black anodized aluminum. nobody could tell you how the anodizing will match crosman black paint unless they have the exact piece you're asking about. variations in anodizing are big depending on pre anodizing finish, what chemicals are used and what dye is used . the bottom silver breech is natural anodized. anodizing is more than just coloring. it imparts a corrosion restance and surface strength to the aluminum. there are also different types of anodizing that impart different qualities to the aluminum. read up on it if you're intrested.
most machine shops won't set up to make 1 custom part. since i make alot of guns , i buy batches of custom parts made to my specs.
search for bobs posts on co2, some good ones on co2 in low temps etc
kj
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Since this is a CO2 gun topic, I was thinking, regarding building up o-rings to control hammer bounce, is it possible to get into a problem with puncturing a newly inserted CO2 cartridge? Obviously depends on the length/number of the o-ring stack. And to a lesser degree, the hammer spring rate.
I have not tried this technique myself. I have been trying the "SSS" that has no preload on the valve stem. Certainly more difficult to cock but a good approach. Have not yet experimented with the "SSG".
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but I'm not really the kind of person that saves up to buy all the good stuff at once. I chose to just buy the 2240 so I could get started and just already have fun shooting it. Finished my tin of 250 pellets today a week after buying it. I'll add upgrades every month probably. Might not be the most efficient way of doing it, but it was the most instantly gratifying way and I'm a millenial. ;D
Slow and methodical is the way to understand what is happening with various changes. Not saying I always do so. :D
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Also, is the CO2 capsule closed off by the piercing thing when the valve is open?
A good question, the short answer is not completely. The question I have always had is how much? Does it really matter as a practical concern? Well, excessive opening of the valve would mean more gas leaving the cartridge during the firing cycle. Other than that not something to worry about. See post #23 above about a potential opposite issue with CO2 cartridge puncturing.
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no, the piercing pin doesn't seal the co2 cartridge. it only drives toward the cart when the hammer hits the valve stem. if using a pro top on the valve the piecing pin is no longer used.
kj
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if you look at the pic of the lpa site you posted , look at the bottom, that is a 3/8" dovetail that is cut perpendicular to the scope rails. here's some pics i took...in the pics with 3 breeches , the middle one is the type that accepts the lps site. the top type has the rear cut to accept the original plastic site, the bottom siver/aluminum has niether. if you can't tell from pics on vendors website if the breech will accept the lpa site, ask them . breeches from crosman also come in a short type that i don't have. never had a desire for less room for mounting optics. i prefer the flat sided type breech, like the silver/aluminum breech for asthetic reasons. i had a dozen special made in aluminum and afew in brass. had the aluminum ones anodized in blue, black and natural. the blue ones i also had engraved. as long as you can mount the optics you like , choice in available breeches is a matter of taste. the crosman ones are the only ones i know of that have the perpendicular dovetail for the lpa site. down side is they only have 1 barrel hold down screw. though an extra one can easily be added.
Ah, the old "we'll sell you this but it only works with this other product of ours" trick. No worries. Do you know of any sights that are similar to the LPA that will fit on a standard dovetail? If not I guess I'll buy the Crosman breech and have an extra hole with threading made like you suggested. I do also like the shape of your aluminium one though. How does the black anodization match up to the blueing (I think it's blueing) on the stock barrel and main tube? Is it the top one in your picture? And what does it mean to anodize something in "natural"? What color does it come out as?
Also, you say you had a dozen special made, how do you mean? Specially made to your specifications? Where did you have this done? Related to my question 6 in my original post. There's a metal workshop on my street, do you think they'll have the equipment there to make something like that for me? I've looked through the window and I saw that they did have the (don't know what it's called in English) horizontal drill machine. What kind of equipment is needed to make stuff like this?
Disco valve = from a Crosman/Benjamin Discovery PCP rifle.... It is the same basic valve as a 22XX valve, with an extended front end, sealed into the tube with O-rings.... Internally, the dimensions are the same as a 22XX valve, but it has a harder poppet to withstand the higher pressures.... I am not suggesting it for your use, there would be no advantage, I just mentioned it because the porting is the same, and the same modifications would apply....
Yes, the idea is to get a smoother, slightly increased gas flow, and then shorten the valve dwell to conserve CO2.... The first part of the impulse does more of the work of accelerating the pellet, and there is no point in keeping the valve open after the pellet leaves the muzzle, of course.... A stock 2240 does exactly that, you can reduce the hammer spring preload and save CO2 without losing any velocity initially....
Here is what happens with a 2240 with a 14" barrel as you change the hammer spring preload.... The 7.5" barrel will benefit less, if at all, from increased preload.... and note it only effects the first few shots anyways, when there is some liquid CO2 getting into the valve (very wasteful) and before the gun cools.... Shots are about 30 seconds apart....
and here is what happens with a 24" barrel showing what you can achieve by tuning to conserve CO2....
Sorry, I don't have similar charts for a 2240 with 7.5" barrel, but you get the idea....
Bob
Ah, got it on the Disco valve. The thing is, Fivestar and kj recommend a pro-top, and fivestar mentioned I should get a Disco valve to go with it. So is the pro-top a modified hammer/striker? Does that mean it can't go with the p-rod trigger as that would require a p-rod hammer/striker that kj posted?
The red line in the lower chart is amazingly flat! What does SSG stand for?
striker hammer are generally the same thing, the difference here is that the p=rod one is 3 pieces, hammer, striker/acetal pin. the acetal pin is just a small piece of nylon that locks the striker from moving on its' own....
the striker is threaded into the hammer and can be adjusted for throw from outside the gun if using the p=rod end cap, which is also 2 pieces and needs one hole drilled and tapped to fit your gun. then the pre-load can also be adjusted.
the crosman website has a section with all the manuals with exploded parts diagrams. you'll need to get familiar with that so you can get parts numbers for ordering. you need them to order, customer service isn't going to look up all the parts for you..lol
peace
kj
I'm not sure I quite understand what this is for. What do you mean by "throw", which you said can be adjusted? I think what I'm getting from this is that you can screw the striker deeper into the hammer, so that it's shorter, in order to decrease the amount of time it leaves the valve open. Am I right? It also looks a bit lighter than the stock hammer, does it make any difference in vibrations when firing?
dutch, you also do well to look up some of bobs' , rsterne , past posts on co2, lots of excellent info there for sure, i've leaned alot from him over the years.
fivestar, anthony is also a wealth of info for sure. he produces the pro top. using the protop allows removal of the piercing pin and gives a straighter co2 flow path. worth considering.
hats off to bob and anthony
peace
kj
Awesome to see both of them so willing to advice me. Anything in particular that I can read that you think would be comprehensible for me with my current level of understanding?
Sorry for the delay in responding.
I just took a stock 2240 barrel and measured it for the barrel band and muzzle brake to get my length and chopped it off then recrowned it. I wasn't going for shot count or power... it was pure "cool". I wanted a stubby and had a bunch of stuff laying around. I must be honest, I did steal a couple parts from Betty Lou's 2260 HPA carbine that the mailman just delivered replacements for today. I think I get 35 or so shots from a C02 and waste a ton of it. The muzzle brake is from a 2260 I think? I've never chronied it so all I can tell you is that anything within 20 meters gets hammered. And those .22 benji destroyers turn into shrapnel. The BHB and shorter hammer spring all but eliminates hammer bounce and possibly flattens the string out some. The power adjuster allows me to have a little more control on shot count. I begin a C02 cart with it backed out the slowly turn it in throughout the shot string until I completely lose POI. I usually end up dry firing 6 - 8 times to empty the remains of the C02 cart for replacing. It's just a fun gun to have in the fishing box or in the glovebox/under the seat. Sometimes we are in our barn/bar/shop/indoor shooting range late in the evening with our scoped plinkers. Various night creatures visit uninvited. Willie G. Stubbs is a great guy to have laying in wait on the shooting bench.
No worries, I don't have time to be on here checking for replies all the time either, but it's ok if this thread moves slowly. I don't have money to buy all the parts at once anyway.
You've certainly achieved the cool factor on that gun. It's illegal to use an airgun in public places here and you can't carry it on you in such a way that it's within easy reach. Otherwise I probably would have made it like yours as well, carry it to the beach and shoot some cans there.
Can you fill me in a bit on the BHB mod? I think I understood that they are hammer O-rings, and they're supposed to reduce hammer bounce? What exactly is the negative effect of hammer bounce?
The Pro-Top has it's own piercing pin so it allows the elimination of a valve stem mounted piercing pin. The stem mounted pin in itself causes shot to shot inconsistencies and requires a minimum striker hit to just puncture the powerlet. As to the use of a Disco stem and valve body... the Disco valve has the same volume as the 2240 however it is a better made valve body . It has a more precision seat that works really well with the harder Disco stem and has the bonus feature of 8/32 anchor screws of which in the case of a 2240 you will only use one which is another improvement in consistency when compared to the small head 6/40 anchor screw that the 2240 comes with that will allow the valve to move from front to back in the tube.
When you buy a power adjuster just be sure that you can actually back it out to less pre load than the original rear tube plug provided..because, again, with a Pro-Top you won't need a repeated hard hit, and heavy striker, because now the only thing the striker will be doing is opening the valve and not piercing the powerlet. And if you use it the harder Disco stem it will respond quicker and with less initial lift shrouding than the OEM soft stem. Another plus is the Pro-Top will allow the valve to be disassembled and parts replaced from the front of the tube without removing the valve..and it doesn't use the little pink face seal that frequently gets pulled out on the end of a powerlet.
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I've been following along because I just bought a Sheridan 2260MB and did the mods on the valve so I'm looking for all the info I can get too. I found this thread from a while back that has some mods and also a slow-mo video of the hammer bounce and thought it would be a good read for the OP.
http://www.gatewaytoairguns.org/GTA/index.php?topic=105520.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=105520.0)
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Here's a little visual aid for the bstaley buffer (bstaley o-ring buffer, BSB, etc).
When you use the Prod hammer/striker assembly you are able to make the striker stand out from the outside edge of the hammer. The outer edge of the hammer makes contact with the stack of o-rings (I think they're #113's) that is at the base of the valve which stops the hammer and absorbs further strikes from rebounds. The striker, because it's adjustable, can be screwed out to adjust how far the valve stem is pushed in from the hammer strike.
Here's a picture of a 2240 valve with 4 o-rings and the tip of the valve stem sticking out.
(http://i1305.photobucket.com/albums/s543/timbyb/image_zpsclzwuisy.jpeg) (http://s1305.photobucket.com/user/timbyb/media/image_zpsclzwuisy.jpeg.html)
I use 5 o-rings so there is almost no contact with the valve stem when the striker is fully recessed. This allows me to increase the amount the valve opens by screwing the striker out. From no contact to as far as the valve will open.
(http://i1305.photobucket.com/albums/s543/timbyb/image_zpsirbwegp7.jpeg) (http://s1305.photobucket.com/user/timbyb/media/image_zpsirbwegp7.jpeg.html)
I think this is the graph I made comparing shot strings of my 2240 before and after the bstaley mod.
Red line is pre, blue line is post. Vertical axis is feet per second, horizontal axis is number of shots. There may be other mods in the mix with these numbers, I can't remember what had or hadn't been done previous to the bsb mod. I may have played with different hammer springs and might have angled the exhaust coming from inside the valve. No matter though, you can see the effect.
(http://i1305.photobucket.com/albums/s543/timbyb/image_zps0qndmrfw.jpeg) (http://s1305.photobucket.com/user/timbyb/media/image_zps0qndmrfw.jpeg.html)
Also there's a HUGE thread covering Bob Sterne's SSG (stopped spring guide) development. He put out a Leap Year challenge to take a stock 2240 and only adding in an SSG, see who could get the most total energy from a single co2 cart. I put the details of my results in that thread. I got around 100 shots at about 4 FPE. I was trying to get the most energy out of the cart so the energy needed to be low so as not to waste co2. When I installed it to use, I brought the fpe per shot up which reduced the number of shots but still gave me more than stock and a much better string.
Blue
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Bob Sterne is the only guy I know that has that special calculator to figure that out.
To calculate what exactly?
this gmac breach will fit the lpa site
about hammer /striker. yes the striker screws in and out of the hammer. the throw is the distance in which the hammer/striker travels to hit the valve stem. the further out the striker the shorter the throw, the shorter the throw, the less power, the less co2 is released by the valve. the hammer is drilled all the way through . when using the p-rod endcap one can stick a long allen wrench in and change the throw without didassembly of the gun. the p-rod end cap also has a spring guide the will screw in and out and can be reached through the back of the p-rod end cap. this part works like a power adjuster by increasing or decreasing hammer spring preload/tension.
the top breech is black anodized aluminum. nobody could tell you how the anodizing will match crosman black paint unless they have the exact piece you're asking about. variations in anodizing are big depending on pre anodizing finish, what chemicals are used and what dye is used . the bottom silver breech is natural anodized. anodizing is more than just coloring. it imparts a corrosion restance and surface strength to the aluminum. there are also different types of anodizing that impart different qualities to the aluminum. read up on it if you're intrested.
most machine shops won't set up to make 1 custom part. since i make alot of guns , i buy batches of custom parts made to my specs.
search for bobs posts on co2, some good ones on co2 in low temps etc
kj
I think I also want to put the bolt on the left side of the gun. I've read that the guy at gmac is easy to work with, maybe he'll be willing to make me one with the cross dovetials and also a left side bolt. If not I think I'll just buy a non-anodized left side breech, and find someone to cut the cross dovetail and anodize it in black.
When you say the hammer is drilled all the way through, do you mean it's hollow in order to make it lighter? I don't think (maybe will change my mind when the time comes) that I really feel the need to be able to change the throw without disassembling the gun. Seems like something I would rather get right once and then leave it as it is, and only change it if it needs to be changed due to other modifications. So I think I would rather choose which power adjuster I want based on looks.
As for anodization, is it only possible on aluminium, or also on other materials? And will it come out looking different depending on the material? After reading your post, I looked at my gun and noticed that the barrel and main tube don't match in color very well either. The barrel is a deeper black. The barrel also has a rougher finish. I've read about people polishing and reblueing (or anodizing, is there a difference?) the whole gun. Does this work to make everything the same color?
This particular machine shop looks like it's run by a few hipsters who just make quirky things, so hopefully with the right approach and payment they'll help me out. If not I'll find someone else. :)
Will try to find those posts, thanks for the tip!
but I'm not really the kind of person that saves up to buy all the good stuff at once. I chose to just buy the 2240 so I could get started and just already have fun shooting it. Finished my tin of 250 pellets today a week after buying it. I'll add upgrades every month probably. Might not be the most efficient way of doing it, but it was the most instantly gratifying way and I'm a millenial. ;D
Slow and methodical is the way to understand what is happening with various changes. Not saying I always do so. :D
Completely agree. Somewhere along the way (before performing the first performance mods) I'll buy a chronograph too. I want to be able to measure what I'm doing.
The Pro-Top has it's own piercing pin so it allows the elimination of a valve stem mounted piercing pin. The stem mounted pin in itself causes shot to shot inconsistencies and requires a minimum striker hit to just puncture the powerlet. As to the use of a Disco stem and valve body... the Disco valve has the same volume as the 2240 however it is a better made valve body . It has a more precision seat that works really well with the harder Disco stem and has the bonus feature of 8/32 anchor screws of which in the case of a 2240 you will only use one which is another improvement in consistency when compared to the small head 6/40 anchor screw that the 2240 comes with that will allow the valve to move from front to back in the tube.
When you buy a power adjuster just be sure that you can actually back it out to less pre load than the original rear tube plug provided..because, again, with a Pro-Top you won't need a repeated hard hit, and heavy striker, because now the only thing the striker will be doing is opening the valve and not piercing the powerlet. And if you use it the harder Disco stem it will respond quicker and with less initial lift shrouding than the OEM soft stem. Another plus is the Pro-Top will allow the valve to be disassembled and parts replaced from the front of the tube without removing the valve..and it doesn't use the little pink face seal that frequently gets pulled out on the end of a powerlet.
I'm still a little bit confused on the Pro-Top. Does anyone have pictures of it? I'm having a hard time finding them with google. I'm not quite sure what it actually is, is it something that's attached to the valve? I suppose the piercing pin on the p-rod is just something that pierces the cartridge as it's screwed into the tube? Can you add a p-rod trigger, p-rod hammer, disco valve, disco stem and a p-rod all together?
Edit: Just noticed that Blue called the p-rod a hammer/striker assembly. I'm having a hard time picturing what it looks like and how it punctures the cartridge.
If I understand correctly, what you're saying is that in my situation I might still get some advantage from a disco valve because it has a thicker screw to keep it in place, and it fits more tightly in the tube, both reducing movement of the entire valve itself? And I might still get some advantage from the disco stem because it's more responsive due to it being harder? Sorry if it seems like I'm asking you to explain the same thing twice, but I just want to make sure I understand this right.
As for the power adjuster, can't you just clip the hammer spring or use a weaker one, to be able to back it out to less preload than the original, with any power adjuster?
I've been following along because I just bought a Sheridan 2260MB and did the mods on the valve so I'm looking for all the info I can get too. I found this thread from a while back that has some mods and also a slow-mo video of the hammer bounce and thought it would be a good read for the OP.
http://www.gatewaytoairguns.org/GTA/index.php?topic=105520.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=105520.0)
I read through that thread, thanks. SSGs really do a lot. I would have never thought hammer bounce was just a big CO2 waster. I saw some talk about an internal SSG. When the time comes hopefully someone will have managed to do this and generously posted how. Maybe someone already has, I didn't read the huge SSG thread. I don't want anything sticking out of the back of the gun too far. On the other hand, if made to look a bit nicer, the piece sticking out of the back in the video and slamming forward looks pretty cool. Also, you can feel and hear the hammer bouncing when you pull the trigger. It feels like that's where the bulk of the vibrations come from, so I guess an SSG can be somewhat of an accuracy mod too.
Here's a little visual aid for the bstaley buffer (bstaley o-ring buffer, BSB, etc).
When you use the Prod hammer/striker assembly you are able to make the striker stand out from the outside edge of the hammer. The outer edge of the hammer makes contact with the stack of o-rings (I think they're #113's) that is at the base of the valve which stops the hammer and absorbs further strikes from rebounds. The striker, because it's adjustable, can be screwed out to adjust how far the valve stem is pushed in from the hammer strike.
Here's a picture of a 2240 valve with 4 o-rings and the tip of the valve stem sticking out.
I use 5 o-rings so there is almost no contact with the valve stem when the striker is fully recessed. This allows me to increase the amount the valve opens by screwing the striker out. From no contact to as far as the valve will open.
I think this is the graph I made comparing shot strings of my 2240 before and after the bstaley mod.
Red line is pre, blue line is post. Vertical axis is feet per second, horizontal axis is number of shots. There may be other mods in the mix with these numbers, I can't remember what had or hadn't been done previous to the bsb mod. I may have played with different hammer springs and might have angled the exhaust coming from inside the valve. No matter though, you can see the effect.
Also there's a HUGE thread covering Bob Sterne's SSG (stopped spring guide) development. He put out a Leap Year challenge to take a stock 2240 and only adding in an SSG, see who could get the most total energy from a single co2 cart. I put the details of my results in that thread. I got around 100 shots at about 4 FPE. I was trying to get the most energy out of the cart so the energy needed to be low so as not to waste co2. When I installed it to use, I brought the fpe per shot up which reduced the number of shots but still gave me more than stock and a much better string.
Blue
Ah, good to see you here too. I saw your SSG thread that Radrob posted. Is that a stock valve and valve stem in the first picture? Would there be any effect of this when doing it without a p-rod hammer/striker. The string you posted in your SSG thread was really amazing though!
I found that huge thread. When I'm going to make an SSG I'm sure this will provide me with all the info and ideas I will need.
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Bob Sterne is the only guy I know that has that special calculator to figure that out.
To calculate what exactly?
It was kinda meant to be funny.... Bob has all those fancy graphs and spreadsheets. He's been the guru for a long time... He's light years ahead of me. I just run mine over a chrony.... sometimes.
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Bob Sterne is the only guy I know that has that special calculator to figure that out.
To calculate what exactly?
It was kinda meant to be funny.... Bob has all those fancy graphs and spreadsheets. He's been the guru for a long time... He's light years ahead of me. I just run mine over a chrony.... sometimes.
You know, before I signed up here, I had been reading here and there, reading about all kinds of different mods, but being lost as to which work together and how exactly they all work, and which would be useful with a 7.5" barrel. I also found a lot of contradictory statements. So I thought, I'll go and try to find the real experts, some people who know everything there is to know about this gun, in one place. I found that place. ;D
Also, as soon as I feel like I have a good understanding of this, I'm gonna write a sort of proposal about what modifications I'm going to do, and what you guys think about it.
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I would say that any thing you do with that short barrel is a waste of C02. From what I've been researching the short barrel waste gas regardless of what you do. If I'm wrong then someone will chime in. If you want a 300FPS gun it might work but it's only good for shooting paper.
You don't have to spend money to get more power and see if you like the power vs C02 usage. Do this mod and see what happens. http://airgununiverse.net/22xxvalve.html (http://airgununiverse.net/22xxvalve.html)
It's gonna be louder than before but you should get a few more FPS. It was a big difference on my 2260MB with a 24" barrel.
There's a reason everyone uses longer barrels===results are so much better both in accuracy and power.
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I would say that any thing you do with that short barrel is a waste of C02. From what I've been researching the short barrel waste gas regardless of what you do. If I'm wrong then someone will chime in. If you want a 300FPS gun it might work but it's only good for shooting paper.
You don't have to spend money to get more power and see if you like the power vs C02 usage. Do this mod and see what happens.
It's gonna be louder than before but you should get a few more FPS. It was a big difference on my 2260MB with a 24" barrel.
There's a reason everyone uses longer barrels===results are so much better both in accuracy and power.
I understand that. I'm not trying to get the best possible efficiency/power possible from this gun, I'm trying to get the best possible with the short barrel. Even if there's just a slight improvement possible, I want that improvement. I might in the future consider a 10" barrel, but no longer than that and for now I want to keep it small, as I already find it to be fairly big for a pistol. Especially because I'm also going to add a moderator, I feel a long barrel and also a moderator would make the gun so long that it would make more sense to buy a shoulder stock and turn it into a carbine. The carbines are really cool too though, but this one is going to be a pistol. Don't know if I'll be able to resist building a carbine after this.
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Yes, stock 2240/2250/2260 valve and stem.
I don't think I've heard of anyone using a stock hammer with the BSB mod. I imagine you could eventually find a combination of o-rings or I've heard of people using a small section of hose to get the exact length of a buffer they want. If you can find the length that allows the valve to open the amount you need for the speed you're looking for then contacts the buffer stack and absorbs enough remaining energy to prevent a bounce back forcefull enough to bump open the valve, I think it could work. I think it would be A LOT of work to dial in a tune that way.
The nice thing about the Prod hammer assembly is that it's easier to be able to adjust the striker than disassemble each time to change the buffer in front of the valve.
I think I dialed in the tune I was looking for with a Crosman Challenger power adjuster installed. After I found what I was looking for I removed the power adjuster, clipped the spring to give me a similar spring rate to when it was in the power adjuster but with a stock endcap. I wanted a clean look on the back and wasn't going to adjust it again.
Here's a picture of my 2240, Crosman aficionados can't resist showing pictures of their baby's.
(http://i1305.photobucket.com/albums/s543/timbyb/image_zpsjswqrjat.jpeg) (http://s1305.photobucket.com/user/timbyb/media/image_zpsjswqrjat.jpeg.html)
Blue
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Yes, stock 2240/2250/2260 valve and stem.
I don't think I've heard of anyone using a stock hammer with the BSB mod. I imagine you could eventually find a combination of o-rings or I've heard of people using a small section of hose to get the exact length of a buffer they want. If you can find the length that allows the valve to open the amount you need for the speed you're looking for then contacts the buffer stack and absorbs enough remaining energy to prevent a bounce back forcefull enough to bump open the valve, I think it could work. I think it would be A LOT of work to dial in a tune that way.
The nice thing about the Prod hammer assembly is that it's easier to be able to adjust the striker than disassemble each time to change the buffer in front of the valve.
I think I dialed in the tune I was looking for with a Crosman Challenger power adjuster installed. After I found what I was looking for I removed the power adjuster, clipped the spring to give me a similar spring rate to when it was in the power adjuster but with a stock endcap. I wanted a clean look on the back and wasn't going to adjust it again.
Here's a picture of my 2240, Crosman aficionados can't resist showing pictures of their baby's.
Blue
Very nice looking 2240! Pretty similar to what I'm going to make mine look like. How did you make the front sight go so nicely with the moderator? I'm guessing you used a moderator that slides onto the barrel and just cut the stock front sight and moved it back?
The p-rod sounds good but I'm still wondering if it can go with the pro-top trigger group instead of a pro-top hammer. Waiting for someone to post some pictures of it so I can have a better understanding of it. Another question, in your SSG thread you posted a picture of a notched hammer that came stock in your 2240. Do you know why that notch is there?
Good idea for adjusting with a power adjuster and then clipping the spring. I want to keep the back looking clean as well, either with a brass endcap or a brass power adjuster if it doesn't stick out from the tube too much.
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I'm pretty sure that all the Pro-Top does is pierce the CO2 cartridge when you screw in the front cap, instead of the valve having a piercing pin.... I don't think there is a corresponding trigger group or hammer that they make....
Bob
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NT
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I'm pretty sure that all the Pro-Top does is pierce the CO2 cartridge when you screw in the front cap, instead of the valve having a piercing pin.... I don't think there is a corresponding trigger group or hammer that they make....
Bob
Oh! I see. I thought it was a kind of hammer and also a piercing pin. Got confused there. Ok, so let me check if I finally understand this right. The reasons one would want to eliminate the stock piercing pin by installing a Pro-Top are (1) you can use a lighter hammer spring/less throw/lighter hammer, (2) you can use a Disco valve and stem, which doesn't pierce the cartridge (?), and this stem is better because it's more responsive due to it being a harder material (?).
Do you see anything wrong there? I read back in the previous responses to see if I'm not asking any stupid questions now, but I was a little confused by Fivestar's comment "And if you use it the harder Disco stem it will respond quicker and with less initial lift shrouding than the OEM soft stem." I'm not quite sure what he meant by lift shrouding.
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If I remember correctly when you remove the front sight its a slip on fitting that is centered by way of a flat spot on the end of the barrel and a corresponding flat inside the sight. I think theres a ledge inside the sight which the barrel butts up to keeping the sight from going any further down the barrel.
I carefully drilled out the front sight to eliminate the flat and the ledge which allowed it to slide back exposing the end of the barrel. The LDC is a 5" TKO which presses on the end of the barrel and is secured by a couple set screws so I needed to have a small amount of barrel exposed to get it on.
Leaving the front sight is more for looks since I use the red dot. If I was planning on having the sight functional I'd try to fix it in place with an adhesive or set screws. It doesn't really move but I'd want a little insurance against it rotating without me noticing if I were to rely on it.
Blue
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If you use a Pro-Top (are they even made still?) you can use the back end of a Disco valve, the Pro-Top replaces the front end.... If you then use a Disco poppet, it will open slightly easier (but that is not an issue at CO2 pressures anyways).... Being harder, it may not seal as well if there is any dirt or nicks on the seat.... You can also just fit a Disco poppet into the 22XX valve, instead of buying the whole valve and throwing away the front end....
I think the reference to "lift shrouding" would mean that the Disco poppet, being harder and flatter, will have a slightly smoother path for the CO2 across the seat of the valve, requiring slightly less lift to get the same flow.... This is not really an issue, as you can always add a fraction more preload on the hammer spring to get that lift with a stock poppet....
I don't really see any advantage to using a Disco valve on CO2....
Bob
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If I remember correctly when you remove the front sight its a slip on fitting that is centered by way of a flat spot on the end of the barrel and a corresponding flat inside the sight. I think theres a ledge inside the sight which the barrel butts up to keeping the sight from going any further down the barrel.
I carefully drilled out the front sight to eliminate the flat and the ledge which allowed it to slide back exposing the end of the barrel. The LDC is a 5" TKO which presses on the end of the barrel and is secured by a couple set screws so I needed to have a small amount of barrel exposed to get it on.
Leaving the front sight is more for looks since I use the red dot. If I was planning on having the sight functional I'd try to fix it in place with an adhesive or set screws. It doesn't really move but I'd want a little insurance against it rotating without me noticing if I were to rely on it.
Blue
Yes, that's how the stock front sight works. I think I will try to glue or screw a fibre optic front sight on top of a silencer adapter, and use a threaded moderator. What's your impression of the 5" TKO's performance? I do like its small size.
Another thing I'm thinking about is to make a front sight that consists of a tube, giving me a circle as a front sight enabling me to see through it.
If you use a Pro-Top (are they even made still?) you can use the back end of a Disco valve, the Pro-Top replaces the front end.... If you then use a Disco poppet, it will open slightly easier (but that is not an issue at CO2 pressures anyways).... Being harder, it may not seal as well if there is any dirt or nicks on the seat.... You can also just fit a Disco poppet into the 22XX valve, instead of buying the whole valve and throwing away the front end....
I think the reference to "lift shrouding" would mean that the Disco poppet, being harder and flatter, will have a slightly smoother path for the CO2 across the seat of the valve, requiring slightly less lift to get the same flow.... This is not really an issue, as you can always add a fraction more preload on the hammer spring to get that lift with a stock poppet....
I don't really see any advantage to using a Disco valve on CO2....
Bob
Wouldn't a Disco poppet, giving a smoother path for the CO2, achieve the same thing as widening the transfer port and angleing the valve "outlet" (forgive me if I'm using the wrong terms)? That is, hopefully, getting more gas behind the pellet faster before it leaves the barrel? I think what I want to try is to make the flow of the CO2 as smooth as possible, and then adjust the force of the hammer hitting (in the various ways described here) so that it doesn't waste any CO2.
Do you think the idea of getting the gas out of the valve and into the barrel as fast as possible is conceptually sound for increasing FPS, however slight? What I mean by this is that hopefully I can use a lower volume of CO2 per shot to increase efficiency, but getting that lower volume into the barrel faster to offset any losses in velocity by using less CO2, or potentially even gaining a (very) small increase in average FPS (not total cumulative FPS) while also gaining efficiency.
Edit: I put one piece of your reply in bold text, that's the reason why I'm asking this.
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I like the 5" TKO, although I've never tried any other size. I too didn't want anything longer than it needed to be.
I've heard that the longer ones are better for higher power rifles but the 5" allows me to shoot quietly in the basement without disturbing anyone above.
I'm pretty sure TKO (www.TKO22.com (http://www.TKO22.com)) makes threaded versions in fact I think he makes one for the Maximus (I think only the Euro Hunter model is the version that comes with a threaded adaptor). You could see if you can order one from Crosman, I don't know if the Maximus barrel and the 2240 barrel are the same OD. Prices are cheap, flat $4 shipping, you just have to find the correct part number by going through their EVP's on the website. You could also call him to see if he has any recommendations for an adaptor that will interface with your barrel and his LDC.
I've heard good things about Rocker1's custom shrouds and LDC's. He's one of the moderators here, you could look him up and send him a message inquiring what he might be able to offer.
Blue
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Not really.... the flow around the poppet is two 90* turns within a very short distance, and the flow area is dependant on the lift.... In the case of the softer, stock poppet, is gets a bit of a "groove" in it (because it's soft), so it has to open a bit further to get the same area for flow.... There might be a theoretical advantage to using a Disco poppet, but I defy you to be able to measure it.... and it is more prone to leaking on CO2 because of the lower pressure and the dirt sometimes found in CO2 cartridges....
Smoothing the flow BEHIND the valve throat, by angling the port and rounding the bottom end is altering something that is of fixed dimensions, you don't have the option of just opening the valve a few thou further like you do with the poppet.... Better flow there will deliver the CO2 that the valve releases to the pellet in a more efficient manner....
Bob
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If you use a Pro-Top (are they even made still?) you can use the back end of a Disco valve, the Pro-Top replaces the front end.... If you then use a Disco poppet, it will open slightly easier (but that is not an issue at CO2 pressures anyways).... Being harder, it may not seal as well if there is any dirt or nicks on the seat.... You can also just fit a Disco poppet into the 22XX valve, instead of buying the whole valve and throwing away the front end....
I think the reference to "lift shrouding" would mean that the Disco poppet, being harder and flatter, will have a slightly smoother path for the CO2 across the seat of the valve, requiring slightly less lift to get the same flow.... This is not really an issue, as you can always add a fraction more preload on the hammer spring to get that lift with a stock poppet....
I don't really see any advantage to using a Disco valve on CO2....
Bob
Yes the Pro-Top's are still around. And the Disco valve seat and stem combination do seal and work well at co2 pressures. I have found that Disco stems do not seal reliably in a 22xx valve body as the 22xx seats that I've seen usually have nicks and marks in them that usually only seal with a softer more compliant stem.
For the folks that haven't seen a Pro-Top here are a few pic's.
From the left Pro-Top on a Boss valve Disco valve ,22xx, and an OEM 22xx
(http://i494.photobucket.com/albums/rr305/rainmaker20/Pro-Top/all4.jpg) (http://s494.photobucket.com/user/rainmaker20/media/Pro-Top/all4.jpg.html)
Here's what is in them
(http://i494.photobucket.com/albums/rr305/rainmaker20/Pro-Top/Pro-Topbreakdown.jpg) (http://s494.photobucket.com/user/rainmaker20/media/Pro-Top/Pro-Topbreakdown.jpg.html)
Looking into the captured powerlet seal and piercing pin
(http://i494.photobucket.com/albums/rr305/rainmaker20/Pro-Top/InsidePro-Top.jpg) (http://s494.photobucket.com/user/rainmaker20/media/Pro-Top/InsidePro-Top.jpg.html)
Here are some before and after chrony strings I did on a brand new bubbly pack 2240. All that was done was to cut the piercing pin off the OEM stem with a Dremel. These were done in about 68deg f basement no time taken between shots just loaded and shot. As can be seen the test pellets were Hobbies which will be a bit faster in both tests.
(http://i494.photobucket.com/albums/rr305/rainmaker20/Pro-Top/Pro-TopString.jpg) (http://s494.photobucket.com/user/rainmaker20/media/Pro-Top/Pro-TopString.jpg.html)
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I like the 5" TKO, although I've never tried any other size. I too didn't want anything longer than it needed to be.
I've heard that the longer ones are better for higher power rifles but the 5" allows me to shoot quietly in the basement without disturbing anyone above.
I'm pretty sure TKO makes threaded versions in fact I think he makes one for the Maximus (I think only the Euro Hunter model is the version that comes with a threaded adaptor). You could see if you can order one from Crosman, I don't know if the Maximus barrel and the 2240 barrel are the same OD. Prices are cheap, flat $4 shipping, you just have to find the correct part number by going through their EVP's on the website. You could also call him to see if he has any recommendations for an adaptor that will interface with your barrel and his LDC.
I've heard good things about Rocker1's custom shrouds and LDC's. He's one of the moderators here, you could look him up and send him a message inquiring what he might be able to offer.
Blue
I did some searching on google, and I think that the adapter that I posted in my original post, is actually a Maximum adapter being sold as a 2240 adapter by the Dutch webshop where I found it. So that might work, but I'll do a little more research before I buy. Thanks for the leads.
I'm gonna have to decide between a smaller silencer like a TKO for looks (if you say doesn't bother people one floor up it's fine in terms of noise), or a bigger one like the Weihrauch which I think I remember reading that the hammer is louder than the CO2 pop with that, which is pretty cool and impressive too. Especially with some efficiency mods (especially the hammer bounce) it could get really quiet that way.
Yes the Pro-Top's are still around. And the Disco valve seat and stem combination do seal and work well at co2 pressures. I have found that Disco stems do not seal reliably in a 22xx valve body as the 22xx seats that I've seen usually have nicks and marks in them that usually only seal with a softer more compliant stem.
For the folks that haven't seen a Pro-Top here are a few pic's.
From the left Pro-Top on a Boss valve Disco valve ,22xx, and an OEM 22xx
Here's what is in them
Looking into the captured powerlet seal and piercing pin
Here are some before and after chrony strings I did on a brand new bubbly pack 2240. All that was done was to cut the piercing pin off the OEM stem with a Dremel. These were done in about 68deg f basement no time taken between shots just loaded and shot. As can be seen the test pellets were Hobbies which will be a bit faster in both tests.
(Had to remove your images in order to post)
In that shot string, is the increase in power to be attributed to the piercing pin taking up volume in the valve, and so increasing volume by cutting it off? I suppose you did get fewer useable shots with the piercing pin removed?
Also, what's a Boss valve? Another valve from a different gun? It looks the same to me from the outside as a 22xx valve.
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op...seems you have a bit of confusion. the p-rod is a separate pcp pistol made by crosman. so when talking about a p=rod hammer or trigger group , they come from this pistol. again i'll suggest you look at the diagrams on the crosman site to help gain a better understanding of how things work and what things are when people talk about them. also you'll need the part numbers if you order from crosman. many of crosman parts are interchangable. this modular approach makes it easier for crosman and more fun for modders.
the p-rod hammer is drilled through to allow an allen wrench to slide through from the back to make the throw adjustment. there is a place on the treaded part of the striker to accept the allen wrench.
i believe anodizing is only for aluminum. you can look i nto it further.
boss valves ar after market valves that come in the 12gram cartridge stayle and bulk fill style. they're already modded
peace
kj
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op...seems you have a bit of confusion. the p-rod is a separate pcp pistol made by crosman. so when talking about a p=rod hammer or trigger group , they come from this pistol. again i'll suggest you look at the diagrams on the crosman site to help gain a better understanding of how things work and what things are when people talk about them. also you'll need the part numbers if you order from crosman. many of crosman parts are interchangable. this modular approach makes it easier for crosman and more fun for modders.
the p-rod hammer is drilled through to allow an allen wrench to slide through from the back to make the throw adjustment. there is a place on the treaded part of the striker to accept the allen wrench.
i believe anodizing is only for aluminum. you can look i nto it further.
boss valves ar after market valves that come in the 12gram cartridge stayle and bulk fill style. they're already modded
peace
kj
Oh! I was wondering why there were so many different p-rod parts, I thought it was like a whole upgrade kit sold by some little webshop. ;D
I have looked at the exploded view of the 2240 and 2300T. I understand how everything works, but I didn't look very closely at what everything is called. Will do that some more. Also, for anybody reading along now or in the future, this pictures was also quite useful alongside the exploded view to figure out how the gun works:
(https://s-media-cache-ak0.pinimg.com/originals/25/19/e0/2519e0bea783420f83840cf13c9f8e29.jpg)
I looked into the Boss valves, I would probably be better off modding the stock valve if needed.
Edit: Looked it up and a p-rod is a Benjamin Marauder apperantly.