GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Tucobenedicto on November 21, 2019, 02:46:44 PM
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I have a regulated Prod,i am thinking to made a plastic hammer,primarly for smoothness and consistency,the question is :
it worth to try a light hammer setup? Can it improve efficency in some manner?
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I have a regulated Prod,i am thinking to made a plastic hammer,primarly for smoothness and consistency,the question is :
it worth to try a light hammer setup? Can it improve efficency in some manner?
You will have a hard time making power with a lightweight hammer and it has a sear drag system that would really not be good on a MDS hammer
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I have a regulated Prod,i am thinking to made a plastic hammer,primarly for smoothness and consistency,the question is :
it worth to try a light hammer setup? Can it improve efficency in some manner?
You will have a hard time making power with a lightweight hammer and it has a sear drag system that would really not be good on a MDS hammer
Hey Travis don't you have some titanium you need to go thread? lol :P
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Titanium no,maybe i can made a depleted uranium insert ;D
Probably i will try to made a bronze hammer and mill down some material to weight like the original.
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I love this place!
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I don’t own a Prod but I’m 99% sure it has a proper drop sear trigger group like its big brother. If so, fair game for a plastic hammer.
All other things being equal, a short barrel will benefit more from a lightweight hammer than a long barrel because of its influence on dwell. And generally speaking, it’s well suited for regulated setups because they operate at lower pressure. That assumes the porting is reasonable (in the vicinity of 75% of the caliber) which is the necessary ingredient for making decent power at low pressure.
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Jason,i recently upgraded the barrell to a 16,5",the ports are .165 and i am happy with the actual power,the main reason i was thinking about a plastic hammer is to reduce friction and noise,the question about light hammers is to understand pro and cons.
Thank you all for the replies.
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Okay, with a 16.5” barrel running pellets, I would say it’s still a good candidate for a lightweight hammer.
To draw some contrast, where it doesn’t make so much sense is with something like a 25+ inch barrel running heavy slugs where you need a lot of dwell to accelerate a larger mass over a longer distance…plus a larger valve throat that is harder to knock open in the first place.
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Ok,i suppose a light hammer requires a stiffer spring too,is this right?
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Yes you’ll need more spring force but if you have the ability to adjust spring preload, there’s a good chance you won’t need a new spring.
With a heavy conventional hammer, just cranking up the preload is an invitation for significant hammer bounce. With a lightweight hammer, that propensity is greatly diminished…but you can of course pair it with an SSG if you want.
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Been a busy morning ...
In these 5/8" I.D. air tubes it is really tough to get sufficient hammer weight using a plastic for the .22 caliber P-rod. While i personally have had great success doing so in .177 caliber ( 1701-1720 ) gun which have been > .20ft-lb applications.
In .22 caliber where your simply needing higher power, an SSG devise would be the better route in pursuit of better efficiency over a LW hammer.
JMO,
Scott
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Thank you Scott for the reply to the call ;)
Unfortunately the stock adapter i have is screwed on the rear cap,not an easy task to implement an SSG system,maybe i must simply be content to make a low friction hammer,mine is a bit gritty at cocking.
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I have used ones from Rocker1 which use a metal core. As mentioned, you need a stronger spring, and the limited space along with the short 1/2” throw, makes your choices very limited. High power is a challenge. I’d talk to David and see how close he can come to the oem weight but have the MDS outer surface.
I’ve used these only in my long tube versions, which are regulated and have mrod triggers and 20” barrels.
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Ah thanks, that’s good info Scott. When I built a .22 cal QB a few months ago and weighed the MDS nylon hammer, it came in at 1/10 that of the OEM hammer. I mean it was downright comical to hold each one and think there was any way the nylon part could do the job. But it did. No problem reaching the same plateau as before by dialing in some additional preload, and naturally it was much quieter. That’s a 0.75” dia hammer rather than 0.63”…in those terms it doesn’t sound like much but when I run the numbers, it amounts to a 44% difference in cross-sectional area so that may indeed have a lot to do with it.
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Ok,many useful inputs,i am focusing simply on low friction now,what do you think about a bronze hammer? off course removing some material to obtain the same weight of the original,generally speaking steel-bronze coupling are good for low friction.
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Maybe some buttons would help with keeping the stock hammer and playing with springs and tension.
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Ah thanks, that’s good info Scott. When I built a .22 cal QB a few months ago and weighed the MDS nylon hammer, it came in at 1/10 that of the OEM hammer. I mean it was downright comical to hold each one and think there was any way the nylon part could do the job. But it did. No problem reaching the same plateau as before by dialing in some additional preload, and naturally it was much quieter. That’s a 0.75” dia hammer rather than 0.63”…in those terms it doesn’t sound like much but when I run the numbers, it amounts to a 44% difference in cross-sectional area so that may indeed have a lot to do with it.
ultralight hammers work very well in QB's. I don't own a PROD, but I believe there is much more room in a QB to maintain hammer mass and stroke. I have a couple 14gram w/ pin hammers I made from peek. One is in my reg'd QB78 PCP (built on a Cothran SS tube), it is the sweetest shooting gun I own, with regard to it's shot cycle. tuned at 30fpe when you pull the trigger it's just a muted click in the action and a pfft out the barrel. I've put thousands of JsB 18gr down the barrel and there is barely a witness mark on the hammer, even with a 2mm stemmed valve. It's some tough stuff!
I tried a peek hammer in my P15, it was ridiculously light and would barely yield 300fps. The P15 hammer is ~20 grams oem and not much stroke to work with in the first place.
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Maybe some buttons would help with keeping the stock hammer and playing with springs and tension.
i considered the button solution,but for me is much more easy to make a bronze hammer from scratch at the lathe,i still have a bronze bar somewere around.
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Since you have a lathe, why not bore out a piece of MDS nylon or PEEK and make a metal insert? The lubricity of plastic and most of the mass...the best of both.
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Or ... You address the valve and how easy it is too crack the poppet loose from seat ??? Smaller the area poppet head has over the throat of valve easier it opens at any given pressure.
When I did my QB 79 was able to get away with a 100% MDS hammer yet still make decent power ... Two fold why, first being the OEM poppet was not used and a replacement made that had substantially less area. Second being the hammer spring now used was that of a higher spring rate.
Combined the valves poppet is hit with much faster speed by the lighter hammer and poppet lifts off the seat easier .... It is a balance act that only trial & error will figure out ? and days end may not work satisfactorily at all.
Point being when it comes to R&D of the if or not an idea, an application or some specific parts combo will yield the required outcome ? ... You simply must put in the time and effort & try !!
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Since you have a lathe, why not bore out a piece of MDS nylon or PEEK and make a metal insert? The lubricity of plastic and most of the mass...the best of both.
This is an option,but i can't find MDS or PEEK rods in small pieces here,i can source Turcite X rods,similar to Delrin but self-lubing.
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I have used the PRod trigger assembly frequently on my builds, and it has a drop sear, not a "snag" sear.... While it is true that there is a light spring that holds the sear up against the hammer, I have never had any problems using an MDS hammer with the PRod trigger.... However, do NOT use a plastic hammer with a 22XX, 13XX, or Disco style trigger.... they will quickly destroy the catch point on the bottom front of the hammer....
The PRod, Disco, 22XX and Maximus, and the QBs, all use tubes with a 3/4" ID (actually 0.745")…. The 5/8" ID tubes are on the 13XX and 2200 series pumpers....
Bob
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Since you have a lathe, why not bore out a piece of MDS nylon or PEEK and make a metal insert? The lubricity of plastic and most of the mass...the best of both.
This is an option,but i can't find MDS or PEEK rods in small pieces here,i can source Turcite X rods,similar to Delrin but self-lubing.
Here you go be sure and use a sharp bit and use the right speed. if you use brass in it knurl the brass and drill it put it in the mds and then turn it to size. David
https://www.mcmaster.com/mds-filled-nylon-6%2f6 (https://www.mcmaster.com/mds-filled-nylon-6%2f6)