[dont_tread_on_me]

Terra:
I installed a JP yellow AR type hammer spring in my XCR and as inticipated it failed to ignite the primers on wolf and silver bear ammo.I was wondering if the hammer intended for the 7.62 would possibly have enough more inertia to work with the lighter spring on the hard primer ammo for succesful ignition.I would love to be able to use it,damn does it help the trigger,but I'm not going to sacrifice reliability to get there.If anyone else has any ideas,please chime in.
Matt

 

[tacweapon]

I don't know about the heavy hammer but a lot of people have got a Bill Springfield trigger job and love it there is a thread on the forum about it.

 

[gunner69]

I recommend the heavy hammer AND a trigger by Bill. If you were near to Alabama I would let you shoot mine. Trigger is NICE, and it makes all the difference. :2cents:

 

[TerraShrewsbury]

There is not enough tension in your new spring to send the hammer forward hard enough. A heavy hammer would probably not fix the problem. We could give it a try, but no promises. :dontknow:

 

[dont_tread_on_me]

Thanks for the replies.Bill has worked the trigger on my ptr91,so I'm familiar with his work.I have already polished the sear/hammer engagement,and the second stage is much improved,It's just the first stage thats still a little heavy.It was just a theory that the heavier hammer would strike harder simply due to having more inertia/speed.Thanks again,by the way Terra how much is the 7.62 hammer?

 

[dont_tread_on_me]

After thinking about this a bit,I think I could be wrong.Actually lightening the hammer might work better,since your increasing speed vs using a heavier hammer to impart more force,9mm vs 45 acp anyone,lol? Thoughts anyone?

 

[Bravo]

Kinetic energy equals mass times the square of velocity.

Don't get that confused with momentum, which equals mass times velocity.

As anyone that has played billiards understands, there are such things as elastic collisions. Like steel-on-steel collisions where no deformation is occuring. So the question becomes - is kinetic energy or momentum better at overcoming the inertia of a firing pin?

The answer would be momentum.

That having been said, the spring produces just so much energy (that's what springs do - retain energy). Reduce the hammer mass, the velocity increases - but since they're equal partners in momentum you've bought yourself nothing in the way of momentum. Kinetic energy is a different matter.

So what this says to me is that Terra was right - your spring more than likely doesn't have enough force to do the job. If you substitute a heavier hammer in with that spring, odds are (as in the previous paragraph) nothing will be accomplished.

 

[dont_tread_on_me]

Damn someone obviously was paying attention in physics class,lol.Thanks for the lesson ;D

 

[TerraShrewsbury]

I :inlove: Stan. ;D

 

[MrChem]

Damn someone obviously was paying attention in physics class,lol.Thanks for the lesson ;D

I wish my physics students retained as much! You make me proud Bravo.

 

[gunner69]

With Foot in Mouth.... I understood you would DISCARD the light spring, return to the stock spring, and install a heavy hammer. :duh: Brovo good catch.... ya gotta say what you mean... and I didn't. :-[

 

[dont_tread_on_me]

OK guys,I found the "grip screw trigger job" on another thread and if anyone here who hasn't sent your lower to Bill for a trigger job,you might want to try this.To put it simply,it kicks ass.The heavy first stage is completely gone.I also used some 600 grit paper on the sear/hammer engagement,and the result is about like the trigger on my 1911.I would guess(no gauge) about five pounds with just a hair take up.I'm anxious to see what kind of groups this thing will print now.Not that it was bad before but the potential is much better now.Thanks again for all the help.
Matt