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5/19/2014 4:01:18 AM EDT
Just finished putting together my M4-22. Chiapa .22 on top, omni bottom with Alpha parts.

Seems to function in every way except resetting the hammer when fired. Charge handle, fire, it cycles, extracts, loads, but the trigger locks like its not been cocked. If If I rack the charge again, it xtracts the live round and feeds a new one and cocks the hammer and fires just fine.

What might be happening? If I turn it on its left side, it runs better...which is weird.
And what's a good fix for this? Find a way to raise the hammer a little? Just not sure. Loosen the hammer spring a bit for less resistance?

Thanks!
5/19/2014 4:05:17 AM EDT
[#1]
what ammo ?
5/19/2014 6:22:16 AM EDT
[#2]
Federal 40gr 1200fps. Generic basically. Think I need more pop?
5/19/2014 8:14:25 AM EDT
[#3]
are you using a notched ar-15 hammer ?
5/19/2014 12:47:51 PM EDT
[#4]
Quote History
Quoted:
are you using a notched ar-15 hammer ?
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I'll look, but now that you mention it I dont think it is. I think the face of the hammer is smooth.
5/20/2014 9:39:43 AM EDT
[#5]
I ask cause notched hammers have been known to cause some issues just like you described ... sometimes ... you could also go with one of these blow back hammers
I have heard good things about them
5/20/2014 9:12:43 PM EDT
[#6]
Quote History
Quoted:
I ask cause notched hammers have been known to cause some issues just like you described ... sometimes ... you could also go with one of these blow back hammers
I have heard good things about them
View Quote


These are designed to only work with New Frontier Armory polymer lowers and will not work with a standard trigger, FYI.
5/21/2014 5:43:49 AM EDT
[#7]
Quote History
Quoted:


These are designed to only work with New Frontier Armory polymer lowers and will not work with a standard trigger, FYI.
View Quote View All Quotes
View All Quotes
Quote History
Quoted:
Quoted:
I ask cause notched hammers have been known to cause some issues just like you described ... sometimes ... you could also go with one of these blow back hammers
I have heard good things about them


These are designed to only work with New Frontier Armory polymer lowers and will not work with a standard trigger, FYI.


is that cause they dont want a poly hammer one a metal disco ?
5/21/2014 6:43:39 AM EDT
[#8]
Wondering if I could grind down the hammer a bit to make it lighter. Since its .22 its not taking a lot of brute force. Anyone think cutting the weight down might do it?
What about a lighter spring? Or both? (The spring in there now is pretty damn stiff. )
5/21/2014 7:06:22 AM EDT
[#9]
The problem is that the rifle can short stoke to not cock the hammer back to the disco, while still getting the bolt past the back of the rim of the live round to pick up a new round and charge it.


Lighter hammer spring, lighter recoil spring, as well as polishing the parts will help the rifle to full stroke correctly, and/or as well as just using CCI mini mag ammo to break the rifle in until the parts self polish out to insure that the action is full stroking.

Also to point out, make sure that the disco spring has been installed large coil side down into the hammer slot under the tail of the disco.  If you have the spring installed the wrong way, cause be causing the fail to full stoke, as well as if the spring is not installed, the hammer will not be caught by the disco for trigger release hammer reset.
5/21/2014 7:49:16 AM EDT
[#10]
Very cool. Thank you!!! Will be giving all this a try.
5/21/2014 6:46:52 PM EDT
[#11]
Quote History
Quoted:


is that cause they dont want a poly hammer one a metal disco ?
View Quote View All Quotes
View All Quotes
Quote History
Quoted:
Quoted:
Quoted:
I ask cause notched hammers have been known to cause some issues just like you described ... sometimes ... you could also go with one of these blow back hammers
I have heard good things about them


These are designed to only work with New Frontier Armory polymer lowers and will not work with a standard trigger, FYI.


is that cause they dont want a poly hammer one a metal disco ?


The NFA Polymer fire control group is a proprietary one, just like a RRA 2 stage. The parts don't interchange (intentionally) with standard fire control groups.
5/22/2014 5:17:44 AM EDT
[#12]
good to know then thanks for the info joebob
6/6/2014 4:55:11 AM EDT
[#13]
In case anyone sees this in the future with the same issue.

It was the disconnector spring. It was setting in a weird position... turned flat.  I decided to take the lower apart and just redo it. Noticed it first thing when I pulled the hammer.

No issues. Now if I can find some reliable mags for it.....
6/10/2014 3:51:11 PM EDT
[#14]
I had very good luck with Black Dog magazines when I had a Chiappa upper.
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