GTA
Airguns by Make and Model => Daisy Airguns => Topic started by: DavidS on October 12, 2015, 01:03:39 AM
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I am going to eventually get a proper chrony, as soon as money allows.
Though I ask what are the potential limits of the Daisy 880? Any one that has done power modifications and chronied, how much power have you been able to get?
Is 12FPE (830FPS with 7.9 grain pellets, or 730FPS with 10.5 grain pellets) a reasonable goal?
Does it seem like the power plant may be able to be pushed far enough to produce 14.8FPE (950FPS with 7.4 grain pellets), the absolute maximum usable level with .177 in my opinion (beyond that you are getting a little close to the speed of sound with 7 to 8 grain lead pellets). For that matter would it be possible to reach even higher power (using only heavier pellets)?
The most important question is how far the 880 has already proven itself capable of for power after modification. As that would give reasonable answers to the other questions.
I am fairly sure that 12FPE is a reasonable goal, beyond that I am not sure what my goals should be, hence the question of what has been done and chronied.
Some power mods not previously mentioned that will be attempted with my newest 880 eventually:
It will get all of the power mods that I have posted in the past, as well as Stonykill's aluminum tape modification. It will also receive all the standard accuracy modifications.
Then I will add a new one that I realized possible:
It is possible to increase the effective piston stroke by about 3/16th of an inch further than just shimming the tube for the current piston length, and it is possible to do so with out any custom parts. This is done by cutting the portion of the piston rod that is on the opposite side of the guide wheels from the piston, and then cutting back where the pump arm hits the fore-stocks when open. Once done there would be the need to shim the pump tube even further, to the point of the Valve body O-Ring being barely enough inside the tube to do its job, it would be a risky test the first time.
This new pump stroke modification would make the percentage of wasted head space slightly less, do to the longer stroke, as well as pumping a little more air per stroke.
I am still looking for other possible Power modifications, especially those that do not require any extra pumping. I believe that it is possible to get a lot more power out of the Daisy 880 than has yet been done, and I believe it possible with out making any extreme custom parts.
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Paging Stonykill. He's the guy to ask.
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Sounds like a plan. 8)
I'm guessing a longer barrel isn't in the cards?
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Sounds like a plan. 8)
I'm guessing a longer barrel isn't in the cards?
No long barrel for this one.
Though there will come a point when that is the only remaining way to increase the ME.
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I am going to eventually get a proper chrony, as soon as money allows.
Though I ask what are the potential limits of the Daisy 880? Any one that has done power modifications and chronied, how much power have you been able to get?
Is 12FPE (830FPS with 7.9 grain pellets, or 730FPS with 10.5 grain pellets) a reasonable goal?
Does it seem like the power plant may be able to be pushed far enough to produce 14.8FPE (950FPS with 7.4 grain pellets), the absolute maximum usable level with .177 in my opinion (beyond that you are getting a little close to the speed of sound with 7 to 8 grain lead pellets). For that matter would it be possible to reach even higher power (using only heavier pellets)?
The most important question is how far the 880 has already proven itself capable of for power after modification. As that would give reasonable answers to the other questions.
I am fairly sure that 12FPE is a reasonable goal, beyond that I am not sure what my goals should be, hence the question of what has been done and chronied.
And the 880 has a lot to offer if you do not mind doing some low cost simple work on it. There are a good number of 12FPE+ Daisy 880's around now. You really are not likely to ever need that much power though.
Was this just a guess last week? You were telling everyone that "lots" of them exist, now you are questioning if it's even possible?
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Good point Rob.
I USED to have a chrony. I lent it to one of my only friends and he shot it with a crossbow. He will replace it, but it may tke him a while.
I have yet to chrony each mod individually. I need to do this. There are interweb claims that the hammer mod adds FPS. I do it. But I have to question how it does anything. If you look at how an 880 fires, the valve opens and stays open until you cycle the bolt. Now this hammer mod is supposed to work by letting more air out. Which to me makes no sense as the valve does not open and close upon firing. It just opens. PERHAPS it helps by clearing a little more unrestricted room for air to flow out smoothly, as in less turbulance. I have my doubts this mod actually does anything personally. Something to check in the future.
But to the point. Yes 12 FPE is achievable in .177. I did it once.
I have built 2 14 FPE .22 Daisy's. One is my LW barrelled 880, my main hunting weapon. The other is in a 901 Rob/Bigtinboat generously gifted me. Although those internals were in an 880 already. Both of those were built in the spring and were chronied in the mid 660's with a 14.3 grain pellet.
After snow flies i'll be spending more time on the 880's, 901's and 35's making great hunting weapons. Right now my free time is consumed hunting with my 2 .22 880's, my .22 901 and my 9.5 FPE rifled barrel Daisy 35.
There is more power to be had. I'll find it. I don't know how much more with basic tools and no machining of expensive parts, which defeat the purpose of modding a $40 AG.
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There is more power to be had. I'll find it. I don't know how much more with basic tools and no machining of expensive parts, which defeat the purpose of modding a $40 AG.
Tom - if the possibility of more power is there, I know YOU will be the one to find it.
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How loud would the 10+fpe 880s be? Say on the Pyramyd 1-4 loudness scale?
The more I read about the 880 the more I want one! But I'd need it to be reasonably backyard quiet for intended purposes.
Thanks!!
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How loud would the 10+fpe 880s be? Say on the Pyramyd 1-4 loudness scale?
The more I read about the 880 the more I want one! But I'd need it to be reasonably backyard quiet for intended purposes.
Thanks!!
I'll be honest and admit I have no idea what the Pyramyd 1-4 loudness scale is. I assume it is from the blog? I really don't follow that. I get my reviews from real users here on GTA before purchasing something new. If it is from the sight itself, I just never noticed it.
My loudest 880, the 14 FPE .22 carbine sounds like a very loud stick snap in the woods. The kind of snap you hear deer hunting. The loud snap.
The .177's are really not THAT much louder than a stock 880. The stock 880 has a pretty good "snap" to it when fired.
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How loud would the 10+fpe 880s be? Say on the Pyramyd 1-4 loudness scale?
The more I read about the 880 the more I want one! But I'd need it to be reasonably backyard quiet for intended purposes.
Thanks!!
I'll be honest and admit I have no idea what the Pyramyd 1-4 loudness scale is. I assume it is from the blog? I really don't follow that. I get my reviews from real users here on GTA before purchasing something new. If it is from the sight itself, I just never noticed it.
My loudest 880, the 14 FPE .22 carbine sounds like a very loud stick snap in the woods. The kind of snap you hear deer hunting. The loud snap.
The .177's are really not THAT much louder than a stock 880. The stock 880 has a pretty good "snap" to it when fired.
The PA website has a loudness scale of 1-5 in the specification section for most airguns . the stock 880 is rated a 3 .
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In that case a hot rodded .177 880 I would call a 3.5
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Thanks guys! As I mentioned, loudness is a consideration for me when it comes to hot rodding an 880.
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I am going to eventually get a proper chrony, as soon as money allows.
Though I ask what are the potential limits of the Daisy 880? Any one that has done power modifications and chronied, how much power have you been able to get?
Is 12FPE (830FPS with 7.9 grain pellets, or 730FPS with 10.5 grain pellets) a reasonable goal?
Does it seem like the power plant may be able to be pushed far enough to produce 14.8FPE (950FPS with 7.4 grain pellets), the absolute maximum usable level with .177 in my opinion (beyond that you are getting a little close to the speed of sound with 7 to 8 grain lead pellets). For that matter would it be possible to reach even higher power (using only heavier pellets)?
The most important question is how far the 880 has already proven itself capable of for power after modification. As that would give reasonable answers to the other questions.
I am fairly sure that 12FPE is a reasonable goal, beyond that I am not sure what my goals should be, hence the question of what has been done and chronied.
And the 880 has a lot to offer if you do not mind doing some low cost simple work on it. There are a good number of 12FPE+ Daisy 880's around now. You really are not likely to ever need that much power though.
Was this just a guess last week? You were telling everyone that "lots" of them exist, now you are questioning if it's even possible?
I see the misunderstanding, and so apologize. There are a lot of Daisy 880's that have been modded to achieve 12FPE with heavy pellets. I am interested to know what is possible across the board from 7 grain pellets on up to 15 grain pellets. That means also with the lighter weight pellets.
Every post I have read reporting 12FPE uses heavy pellets (9 grain or heavier). This is why in my post at the start of this thread I mentioned the 7.9 grain pellets, I should have also mentioned the 7.2 and 7.4 grain pellets to help highlight the intention.
I figure if it is reasonable to expect 12FPE as possible with the current set of mods, then it should be reasonable to expect to find 14FPE with the mods not yet discovered.
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Good point Rob.
I USED to have a chrony. I lent it to one of my only friends and he shot it with a crossbow. He will replace it, but it may tke him a while.
I have yet to chrony each mod individually. I need to do this. There are interweb claims that the hammer mod adds FPS. I do it. But I have to question how it does anything. If you look at how an 880 fires, the valve opens and stays open until you cycle the bolt. Now this hammer mod is supposed to work by letting more air out. Which to me makes no sense as the valve does not open and close upon firing. It just opens. PERHAPS it helps by clearing a little more unrestricted room for air to flow out smoothly, as in less turbulance. I have my doubts this mod actually does anything personally. Something to check in the future.
But to the point. Yes 12 FPE is achievable in .177. I did it once.
I have built 2 14 FPE .22 Daisy's. One is my LW barrelled 880, my main hunting weapon. The other is in a 901 Rob/Bigtinboat generously gifted me. Although those internals were in an 880 already. Both of those were built in the spring and were chronied in the mid 660's with a 14.3 grain pellet.
After snow flies i'll be spending more time on the 880's, 901's and 35's making great hunting weapons. Right now my free time is consumed hunting with my 2 .22 880's, my .22 901 and my 9.5 FPE rifled barrel Daisy 35.
There is more power to be had. I'll find it. I don't know how much more with basic tools and no machining of expensive parts, which defeat the purpose of modding a $40 AG.
Thank you. I am glad to know that 12FPE is possible with 7.0 to 7.9 grain pellets in .177. I knew it was easy with 8+ grain pellets, just not the more "standard" weight ones. Would I be correct in assuming that is on 10 or 12 pumps??
I had only seen definite reports of 12FPE with heavier pellets in the past. I could not point to the threads at the moment, though I am sure you could. And I no longer trust many of my past results as I have since learned more of the variables that could effect the accuracy of using sound as a way of measuring the velocity of a pellet (hence why I want a proper chrony, eventually)
This tells me that 14FPE is a reasonable goal, if everything is pushed to the limits.
My understanding of the hammer modification is that it works by opening the valve more quickly, thus allowing the pressure to reach the barrel more quickly, before the pellet has traveled as far down the barrel, as well as giving a more complete opening thus reducing the turbulent flow and improving the air flow into the barrel. I could be completely off, though that is my understanding.
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Thanks guys! As I mentioned, loudness is a consideration for me when it comes to hot rodding an 880.
The 880 is definitely not quiet. Though it is back yard friendly. The pumping noise of a stock 880 is louder than the muzzle blast, though when shooting it it may not sound that way. And the increase with power mods is not that great.
The big thing about power modding is that you can use fewer pumps to produce the power you need.
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Thanks guys! As I mentioned, loudness is a consideration for me when it comes to hot rodding an 880.
The 880 is definitely not quiet. Though it is back yard friendly. The pumping noise of a stock 880 is louder than the muzzle blast, though when shooting it it may not sound that way. And the increase with power mods is not that great.
The big thing about power modding is that you can use fewer pumps to produce the power you need.
Very helpful response to my ?. Thanks!
I had one about 40 years ago but all I remember is that it hurt my hand to pump it. However, a member in another thread showed me the correct pumping technique to avoid raw knuckles, etc.
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Good point Rob.
I USED to have a chrony. I lent it to one of my only friends and he shot it with a crossbow. He will replace it, but it may tke him a while.
I have yet to chrony each mod individually. I need to do this. There are interweb claims that the hammer mod adds FPS. I do it. But I have to question how it does anything. If you look at how an 880 fires, the valve opens and stays open until you cycle the bolt. Now this hammer mod is supposed to work by letting more air out. Which to me makes no sense as the valve does not open and close upon firing. It just opens. PERHAPS it helps by clearing a little more unrestricted room for air to flow out smoothly, as in less turbulance. I have my doubts this mod actually does anything personally. Something to check in the future.
But to the point. Yes 12 FPE is achievable in .177. I did it once.
I have built 2 14 FPE .22 Daisy's. One is my LW barrelled 880, my main hunting weapon. The other is in a 901 Rob/Bigtinboat generously gifted me. Although those internals were in an 880 already. Both of those were built in the spring and were chronied in the mid 660's with a 14.3 grain pellet.
After snow flies i'll be spending more time on the 880's, 901's and 35's making great hunting weapons. Right now my free time is consumed hunting with my 2 .22 880's, my .22 901 and my 9.5 FPE rifled barrel Daisy 35.
There is more power to be had. I'll find it. I don't know how much more with basic tools and no machining of expensive parts, which defeat the purpose of modding a $40 AG.
Thank you. I am glad to know that 12FPE is possible with 7.0 to 7.9 grain pellets in .177. I knew it was easy with 8+ grain pellets, just not the more "standard" weight ones. Would I be correct in assuming that is on 10 or 12 pumps??
I had only seen definite reports of 12FPE with heavier pellets in the past. I could not point to the threads at the moment, though I am sure you could. And I no longer trust many of my past results as I have since learned more of the variables that could effect the accuracy of using sound as a way of measuring the velocity of a pellet (hence why I want a proper chrony, eventually)
This tells me that 14FPE is a reasonable goal, if everything is pushed to the limits.
My understanding of the hammer modification is that it works by opening the valve more quickly, thus allowing the pressure to reach the barrel more quickly, before the pellet has traveled as far down the barrel, as well as giving a more complete opening thus reducing the turbulent flow and improving the air flow into the barrel. I could be completely off, though that is my understanding.
Well to be honest I have little interest in further testing of 7 grain pellets. I hunt with CPUM'S. I demand accuracy from a hunting rifle. My average shot as well as my range is 18 yards. If I can't make 1 ragged hole with an AG at that range, It WON'T hunt. And I have yet to find a light pellet that will do that from my 880's. I know you love Winnie domes, me not so much. Out of all of my 880's, 901's, 35's etc, I only have 1, yup ONE 880 that will shoot winnie domes into one ragged hole at 18 yards. So I use them for rough sighting in, and testing purposes only. I hunt with 10.5 grain CPUM's from the box.
As for the hammer mod, opening it quicker does not make sense. With the way a Daisy fires, pull the trigger, the trigger clears the hammer and activates the spring which then in turn opens the valve. And it opens immediately. So to say the hammer mod gets the valve open while the pellet is still not too far down the barrel is simply illogical. The pellet won't move, period until the valve is open. So that portion simply can not be true.
Less restrictive air flow....possibly. I seriously have my doubts that that particular mod does anything. But I'll test it out for sure this winter.
Also in my thought process is this. Since day one of the 880, Daisy has taken the time to machine that little groove in the hammer we are filling. Even back in the day before all of the restrictions added to reduce speed. I simply can not imagine Daisy spending the extra money/labor/tooling to make such a simple part more difficult to make. But hey, who knows I have been wrong before. Point being it would be easier to just cast the part and NOT machine the groove the valve activates from.
David, I could swear that a year, year and 1/2 ago you were posting what you said were chrony numbers, both before and after you sighted phonebooks and sound as your numbers sources. If nothing else, your mods posts made it sound that way.
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Good point Rob.
I USED to have a chrony. I lent it to one of my only friends and he shot it with a crossbow. He will replace it, but it may tke him a while.
I have yet to chrony each mod individually. I need to do this. There are interweb claims that the hammer mod adds FPS. I do it. But I have to question how it does anything. If you look at how an 880 fires, the valve opens and stays open until you cycle the bolt. Now this hammer mod is supposed to work by letting more air out. Which to me makes no sense as the valve does not open and close upon firing. It just opens. PERHAPS it helps by clearing a little more unrestricted room for air to flow out smoothly, as in less turbulance. I have my doubts this mod actually does anything personally. Something to check in the future.
But to the point. Yes 12 FPE is achievable in .177. I did it once.
I have built 2 14 FPE .22 Daisy's. One is my LW barrelled 880, my main hunting weapon. The other is in a 901 Rob/Bigtinboat generously gifted me. Although those internals were in an 880 already. Both of those were built in the spring and were chronied in the mid 660's with a 14.3 grain pellet.
After snow flies i'll be spending more time on the 880's, 901's and 35's making great hunting weapons. Right now my free time is consumed hunting with my 2 .22 880's, my .22 901 and my 9.5 FPE rifled barrel Daisy 35.
There is more power to be had. I'll find it. I don't know how much more with basic tools and no machining of expensive parts, which defeat the purpose of modding a $40 AG.
Thank you. I am glad to know that 12FPE is possible with 7.0 to 7.9 grain pellets in .177. I knew it was easy with 8+ grain pellets, just not the more "standard" weight ones. Would I be correct in assuming that is on 10 or 12 pumps??
I had only seen definite reports of 12FPE with heavier pellets in the past. I could not point to the threads at the moment, though I am sure you could. And I no longer trust many of my past results as I have since learned more of the variables that could effect the accuracy of using sound as a way of measuring the velocity of a pellet (hence why I want a proper chrony, eventually)
This tells me that 14FPE is a reasonable goal, if everything is pushed to the limits.
My understanding of the hammer modification is that it works by opening the valve more quickly, thus allowing the pressure to reach the barrel more quickly, before the pellet has traveled as far down the barrel, as well as giving a more complete opening thus reducing the turbulent flow and improving the air flow into the barrel. I could be completely off, though that is my understanding.
Well to be honest I have little interest in further testing of 7 grain pellets. I hunt with CPUM'S. I demand accuracy from a hunting rifle. My average shot as well as my range is 18 yards. If I can't make 1 ragged hole with an AG at that range, It WON'T hunt. And I have yet to find a light pellet that will do that from my 880's. I know you love Winnie domes, me not so much. Out of all of my 880's, 901's, 35's etc, I only have 1, yup ONE 880 that will shoot winnie domes into one ragged hole at 18 yards. So I use them for rough sighting in, and testing purposes only. I hunt with 10.5 grain CPUM's from the box.
As for the hammer mod, opening it quicker does not make sense. With the way a Daisy fires, pull the trigger, the trigger clears the hammer and activates the spring which then in turn opens the valve. And it opens immediately. So to say the hammer mod gets the valve open while the pellet is still not too far down the barrel is simply illogical. The pellet won't move, period until the valve is open. So that portion simply can not be true.
Less restrictive air flow....possibly. I seriously have my doubts that that particular mod does anything. But I'll test it out for sure this winter.
Also in my thought process is this. Since day one of the 880, Daisy has taken the time to machine that little groove in the hammer we are filling. Even back in the day before all of the restrictions added to reduce speed. I simply can not imagine Daisy spending the extra money/labor/tooling to make such a simple part more difficult to make. But hey, who knows I have been wrong before. Point being it would be easier to just cast the part and NOT machine the groove the valve activates from.
David, I could swear that a year, year and 1/2 ago you were posting what you said were chrony numbers, both before and after you sighted phonebooks and sound as your numbers sources. If nothing else, your mods posts made it sound that way.
Interesting my newest 880 does not seem to care for Winchester Domed, a first for me.
I see your logic in the hammer. I thought it made sense that if the valve begins opening sooner on the spring throw it would take less time to go from closed to open (it does take time to move). That is that the amount of time between the initial cracking and full open would be less. Just my understanding of what is supposed to happen. Though it does make sense that Daisy would not do the extra step with out good reason.
As to my old Chrony numbers, those were done the old fasioned method of recording the sound of the shot and measuring the time between muzzle blast and impact, with the mic an equal distance from both muzzle and target. I no longer trust those numbers as I have since learned that there are a number of variables that can throw off those results. Thus why I need a proper Chrony, I have borrowed one a couple of times in the past, as noted in a couple of threads of the past.
I thank you for your input.
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I don't have a chrony, but use penetration through various media at different distances to indicate power levels.
Gives me a good idea at what distance I believe an airgun might be effective against critters of varying toughness.
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I see your logic in the hammer. I thought it made sense that if the valve begins opening sooner on the spring throw it would take less time to go from closed to open (it does take time to move). That is that the amount of time between the initial cracking and full open would be less. Just my understanding of what is supposed to happen. Though it does make sense that Daisy would not do the extra step with out good reason.
Again, does not make sense to me. The amount of time between initial crack and full open can not change by adding a shim to the hammer. Crack to open is the same amount of throw with or without a shim on the hammer. This does not change. Open further, yes, open quicker. No. Only a heavier hammer spring or a lighter valve spring can do that.
So the ONLY thing that can make sense is it restricts flow less. I'll over the winter try, in the same 880 or 35 with a modded hammer and a stock hammer and see if there is any difference at all in FPS.
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I see your logic in the hammer. I thought it made sense that if the valve begins opening sooner on the spring throw it would take less time to go from closed to open (it does take time to move). That is that the amount of time between the initial cracking and full open would be less. Just my understanding of what is supposed to happen. Though it does make sense that Daisy would not do the extra step with out good reason.
Again, does not make sense to me. The amount of time between initial crack and full open can not change by adding a shim to the hammer. Crack to open is the same amount of throw with or without a shim on the hammer. This does not change. Open further, yes, open quicker. No. Only a heavier hammer spring or a lighter valve spring can do that.
So the ONLY thing that can make sense is it restricts flow less. I'll over the winter try, in the same 880 or 35 with a modded hammer and a stock hammer and see if there is any difference at all in FPS.
Thank you for pointing that out. I guess the amount of preload on the spring when the hammer begins to open would not make a difference with the way the Daisy 880 works, and definitely do see your point. Thank you. I am very interested to see what the difference is.
I guess that means that I will have to separate the two hammer mods (the washer shim and weakening the valve spring while putting in a stronger hammer/trigger spring). Also means that I will have to save the hammer washer shim until after I have a chrony, so I can also see the difference. I will still be pushing ahead with the other modifications on this newest 880.
Once I have a chrony I will be interested in getting a few new 880's to mod one step at a time in different orders to see what has the most effect, and what has no effect.
Once again your input makes perfect sense. I look forward to seeing what the results are. I also look forward to seeing what your next power mod to add to the list will be, as you have come up with more than I have.
To make sure that I am aware of the current complete list:
Does the following cover all the power mods, that are so far known?
- Install Stronger Hammer Spring.
- Weaken Valve Spring.
- Fill limiter slot in piiston with epoxy.
- Cut piston to true flat, and use aluminum tape to make correct length (with aluminum tape coming back to the start of O-Ring slot).
- Bore out transfer port to 0.125 inches.
- Cut piston rod and forward fore stock to allow greater travel (by about 0.1875 inches).
- Shim pump tube forward by about 0.25 inch (give or take depending on particular 880).
- Fill most of gap between the metal check seal cap and pump tube wall ahead of cup seal, with appropriate material (lead works with great care, so does delrin though more work, PLA seems to work well also).
- Shim magnet in bolt forward a bit.
- Epoxy horshue cut washer into hammer slot.
And does the following cover all the known accuracy modifications, that are easy?
- Tape the barrel to fit snug in shroud.
- Debur the barrel lead.
- Shim the magnet on the bolt forward.
- Bore the transfer port to about 0.125 inches.
- Remove the flat spring.
- Polish the contact points.
- Add an over travel adjustment screw for the trigger.
- Add a better sighting device.
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I don't have a chrony, but use penetration through various media at different distances to indicate power levels.
Gives me a good idea at what distance I believe an airgun might be effective against critters of varying toughness.
For my personal knowledge of the ability and improvement of an Air Rifle I do the same. Though for sharing the improvement in a way that is easy to communicate the difference a chrony helps a lot.
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To make sure that I am aware of the current complete list:
Does the following cover all the power mods, that are so far known?
- Install Stronger Hammer Spring.
- Weaken Valve Spring.
- Fill limiter slot in piiston with epoxy.
- Cut piston to true flat, and use aluminum tape to make correct length (with aluminum tape coming back to the start of O-Ring slot).
- Bore out transfer port to 0.125 inches.
- Cut piston rod and forward fore stock to allow greater travel (by about 0.1875 inches).
- Shim pump tube forward by about 0.25 inch (give or take depending on particular 880).
- Fill most of gap between the metal check seal cap and pump tube wall ahead of cup seal, with appropriate material (lead works with great care, so does delrin though more work, PLA seems to work well also).
- Shim magnet in bolt forward a bit.
- Epoxy horshue cut washer into hammer slot.
As to number 4 (the flat topping piston and using aluminum tape to compensate):
I realize that it may be easier to use PLA to go from the front of the O-Ring to the true flat portion of the piston head. This would make it possible to get rid of almost all of the head space created between the area in front of the O-Ring on the piston and behind the piston face, as between the piston and pump tube in this area. Could use an extra pump tube to mold the PLA to perfection, giving only the width of the layer of oil used to prevent the PLA from sticking to the pump tube during molding.
I would think that just barely starting into the O-Ring slot would be enough to hold the new perfect molded PLA shim in place permanently. Maybe ABS would be a better option, though PLA should do the job.
Just a thought. I would like to get the head space as close to 0% of the pump volume as possible. Also why I wish to see how far the total piston stroke can be increased with out custom parts, as the longer the piston stroke the lower the percentage of the pump volume is lost to head space and thus the higher possible pressure, and the less air wasted to head space.
So get rid of all possible head space, and increase the pump stroke as far as possible with out custom parts, the pump should end up as efficient as is possible with out making complete custom parts.
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Power, I don't ponder for reasons more suitable to another thread, but accuracy I do think can be improved and I'd bet there will continue to be new ideas presented.
I've been wanting to look at making pumping more consistent by adding oiled bushings at pivot points. Just a thought, haven't checked to see if it practical.
Also perhaps put pump head and abutment inside a 1" tube and polish them against each other so when they hit they will always do it consistently? No clue if there would be practical results to either, just know I am rarely pumping it the same way each time.
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Power, I don't ponder for reasons more suitable to another thread, but accuracy I do think can be improved and I'd bet there will continue to be new ideas presented.
I've been wanting to look at making pumping more consistent by adding oiled bushings at pivot points. Just a thought, haven't checked to see if it practical.
Also perhaps put pump head and abutment inside a 1" tube and polish them against each other so when they hit they will always do it consistently? No clue if there would be practical results to either, just know I am rarely pumping it the same way each time.
For consistency on the 880 there are two primary issues. One is the small slot through which air is drawn into the pump tube, requiring a longer pause at the top of the stroke to maintain consistancy. The other is the under sized transfer port. Though the Daisy 880 is already way way more consistent than most other Air Rifles of a reasonable price, so long as you are careful to pause at the top of each pump stroke.
The transfer port issue is easy to correct with the mentioned modification of boring out the transfer port to 0.125 inches. As to the air inlet slot in the tube, I guess someone could attempt drilling extra holes to allow air in at the same distance from end of tube as the end of the existing slot, and then deburr well.
A complete list of all of the accuracy modifications that I am aware of for the Daisy 880/Daisy 901 is (including some not so easy mods, that I do not otherwise mention):
- Polish the trigger/sear contact points.
- Taper the hammer contact points as described by Stonykill.
- Remove the flat spring.
- Install a trigger overtravel limiting screw.
- Tape the barrel to fit snug in the shroud.
- Shim the magnet in the bolt further forward to seat the pellet further past the transfer port.
- Lead lap the barrel.
- Weight the stock (only helps for shooting unsupported positions).
- Find the best pellet for the particular 880.
- Epoxy around outside of where barrel meets the valve body (there is a small gap there).
- Weaken the valve spring.
- Do the washer shim in hammer mod (questionable).
- UNTESTED/NOT SURE: Drill extra holes to draw in air, same distance from end of pump tube as the end of existing slot, then debur.