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How to get 50-60 more feet per second on a stock barrel 2240
https://www.airgunforum.ca/forums/topic68952-30.html
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Author:  rsterne [ Mon Aug 03, 2015 5:45 pm ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

2240 hammer with 50% of the weight removed....

Image

Bob

Author:  Huck [ Mon Aug 03, 2015 5:55 pm ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

rsterne wrote:
2240 hammer with 50% of the weight removed....

Image

Bob

Very nice! Will that hammer work with a drop sear such as the 1701-P trigger group?. A good looking way to get rid of an ounce of material,for sure...but how does the sear catch,if that hammer is for a stock 2240 trigger group....not sure if there is enough material there to push the sear down enough on a 1701-P trigger?? My little brain can't picture how this hammer would work,but I think I need one!?! Thanks,Huck

Author:  rsterne [ Mon Aug 03, 2015 9:17 pm ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

No, with the 1701 trigger group you would have to hold the trigger down to cock the gun.... but it works fine in a 22XX or Disco.... I just wanted to show how much you have to remove to take off 50% of the weight....

Bob

Author:  Huck [ Tue Aug 04, 2015 6:04 am ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

rsterne wrote:
No, with the 1701 trigger group you would have to hold the trigger down to cock the gun.... but it works fine in a 22XX or Disco.... I just wanted to show how much you have to remove to take off 50% of the weight....

Bob


Sorry for continually asking the basic of questions,but are you saying that the lightened hammer works fine in a 2240,or are you just showing what 50% weight reduction looks like?
I ask because I see no way of the sear latching onto the hammer,if in fact this turned down hammer is for a 2240. Thanks,Huck

Author:  Huck [ Tue Aug 04, 2015 6:10 am ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

I have looked,but I can't find any pictures of a turned down stock 2240 hammer....just trying to figure out what it would like, with maybe 3/4 oz. of material removed...also with the waist filled in. Anyone have pics (or link) of one?Thanks,Huck
*EDIT* What about boring from the side with some sort of end-mill,in between the hammer pin hole and the notch?....then maybe turn down the front portion(valve end) to maybe .375 diameter....would that get rid of enough material?
I am guessing that the 2240 hammer is at least,case hardened and machineable once softened.?Huck

Author:  rsterne [ Tue Aug 04, 2015 10:18 am ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

Yes, they are very hard on the surface, I ground the surface away and then used a Carbide bit, turning from the inside out.... I didn't try annealing it, does that even work with case hardening?....

Bob

Author:  Huck [ Tue Aug 04, 2015 8:59 pm ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

GerardSamija wrote:
The red line indicates about how far I'd grind initially then test. The green line is about where I'd probably end up grinding. Leaving maybe 1mm of steel outside what appears to be the threaded centre. Is that an adjustable hammer bolt in the core? If so, you have a nice tool there for fine tuning depth of hammer strike on the valve stem. Never any need to trim the stem when you have that function, if that's what it is.
Attachment:
reduced_hammer.png


I just got to thinking about utilizing that threaded part in the front of the hammer,once I remove the ground down threaded stub. If I were to install a set screw in from the rear,I could adjust the length of the 'stroke',thus,adjusting how much the valve opens ( since I read that the valve opens too much,wasting gas),through the RVA with an allen wrench and adjust the hammer throw,hopefully without hitting the valve face or running out of hammer pin slot,or hitting the rear of the bolt probe.....would that be more beneficial than removing some valve stem material?.
I would like to play around with this idea of an adjustable hammer,if it's feasible?! Any ideas on that? Thanks,Huck

Author:  GerardSamija [ Tue Aug 04, 2015 9:10 pm ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

That's kind of what I was saying earlier when I asked for confirmation that it was an adjustable hammer. No need to grind off any stem to make stroke depth changes. I'd suggest some blue Loctite on the threads to make sure the adjusted hammer bolt doesn't wander in use.

Author:  rsterne [ Tue Aug 04, 2015 10:22 pm ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

That lightened hammer works perfectly in a 2240, or even a Disco.... The sear latches on the front face....

Bob

Author:  Huck [ Wed Aug 05, 2015 5:51 am ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

GerardSamija wrote:
That's kind of what I was saying earlier when I asked for confirmation that it was an adjustable hammer. No need to grind off any stem to make stroke depth changes. I'd suggest some blue Loctite on the threads to make sure the adjusted hammer bolt doesn't wander in use.


Hi:
Not quite sure how that threaded striker in front of the hammer could be adjusted to allow less opening of the valve.....let's say the stock length hammer,the valve opens 1/16" which is wasting gas and I want it to open 1/32"...if the striker face is, let's say 1/8" thick and it is screwed all the way in,would that not make the hammer,actually longer,opening the valve even more?....maybe there is more to this than I am picking up on...not sure?!
Would I not want the total length of the hammer,when adjusted to be shorter,not longer??
I was thinking the same thing regarding that striker backing out or in during operation...some kind of thread locker(blue) would be needed for sure! Thanks,Huck

Author:  GerardSamija [ Wed Aug 05, 2015 9:03 am ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

Not sure what you mean by the striker face being 1/8" thick, but yes indeed, I meant that you could try adjusting the threaded striker in whatever direction. It ought to be as easily adjusted out as in, no? Back it off enough and there should be a lesser impact on the stem. Unless there is something about that hammer you're not saying, such as that it cannot be adjusted rearward any further? If that were the case I would guess that swapping it for another bolt would solve the problem, or otherwise modifying the thing so that it had a more full range of adjustment.

Author:  Huck [ Wed Aug 05, 2015 9:32 am ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

GerardSamija wrote:
Not sure what you mean by the striker face being 1/8" thick, but yes indeed, I meant that you could try adjusting the threaded striker in whatever direction. It ought to be as easily adjusted out as in, no? Back it off enough and there should be a lesser impact on the stem. Unless there is something about that hammer you're not saying, such as that it cannot be adjusted rearward any further? If that were the case I would guess that swapping it for another bolt would solve the problem, or otherwise modifying the thing so that it had a more full range of adjustment.

Sorry...I sometimes have a hard time describing in words what I want to say.Basically,right now my 1701-P hammer has the threaded hole plugged,where the original striker would go, so I can use it in my 2240.Right now the total length of the hammer is 1.306" long...now if removed the 'plug' and installed the proper striker...not really sure of the thickness,I was using 1/8" as an example. If I screw in the original striker,that would make the whole assembly longer,even if I screwed it in all the way, would that not make valve open more than what is now with the 'short' hammer? Hope that clears things up a bit?! Thanks,Huck

Author:  rsterne [ Wed Aug 05, 2015 11:16 am ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

No, making the hammer longer will open the valve less than it does now.... This is because the hammer cocks through a shorter distance, and hence has less stored energy and momentum when it hits the stem.... It does have increased preload (the result of a strange design quirk), but the net effect is that when you extend the nose of the hammer the valve opens LESS not more....

Bob

Author:  Huck [ Wed Aug 05, 2015 12:06 pm ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

rsterne wrote:
No, making the hammer longer will open the valve less than it does now.... This is because the hammer cocks through a shorter distance, and hence has less stored energy and momentum when it hits the stem.... It does have increased preload (the result of a strange design quirk), but the net effect is that when you extend the nose of the hammer the valve opens LESS not more....

Bob

Thanks!
So how should I go about checking where I need to be regarding some extra feet per second....should I start off with the threaded striker all the way screwed in and then take a few shots over the chrony and keep backing out the striker,one turn at a time and chronying each turn out?Thanks,Huck

Author:  topher1266 [ Fri Aug 07, 2015 10:42 pm ]
Post subject:  Re: How to get 50-60 more feet per second on a stock barrel

What was the benefit of the lighter hammer [by 50%] when all is said and done. With just doing that what is the benefit? NO other mod.

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