cmmg ar 15 22lr upper

larson1385 · February 16, 2018, 10:57 PM

I purchased at auction a complete cmmg 22 wasp upper. The problem is that the firing pin barely makes contact with the rear of the shell. I took the firing pin out and it seems ok. However I have nothing to compare it to. After charging the bolt it appears to also go all the way forward. Any tips for me ?. Thanx

brasscollector · February 17, 2018, 07:01 AM

Clean out the bolt really good. Mine was doing the same thing about a week ago. I cleaned the firing pin channel out and put a dab of oil in it. Did the firing pin return spring come out with the firing pin? If not, I would say it's dirty in there. Make sure there isn't a build up of carbon at the breach end of the barrel where the collar slides over. I bought mine from a friend and he put over 1K rounds through it. He was always complaining about how it would coke up n quit while his 10/22 would go forever without cleaning.

marine6680 · February 17, 2018, 05:36 PM

Clean it well...

If that isn't the problem... If they did like Ruger and made the firing pin in a way that prevent it from impacting the barrel breech face, then it could be out of spec.

Ruger uses a slot that a roll pin rides in. The pin prevents the firing pin from moving too far forward.

It may be similar on yours. You may be able to tweak it if need be.

zukiphile · February 17, 2018, 09:31 PM

Quote:

I purchased at auction a complete cmmg 22 wasp upper. The problem is that the firing pin barely makes contact with the rear of the shell.

Why is this a problem? Are you getting failures to fire?

Are there shims around the shaft of the pin? The seller may have used a Taccom firing pin with shims to keep it from striking the barrel or brass with excess force in order to lengthen the life of the pin.

marine6680 · February 18, 2018, 04:46 AM

That's true... I was just working under the assumption of there being an actual issue with failure to fire.

If not, then there is no problem.

larson1385 · February 18, 2018, 01:23 PM

Thanx folks. I took the bolt completely apart and scrubbed it with some carb cleaner and some very small brushes I grabbed at a gun show. I lubed it up and will head for the range. Live long and prosper.

February 16, 2018, 10:57 PM	#1
larson1385 Junior Member Join Date: July 14, 2014 Posts: 11	cmmg ar 15 22lr upper I purchased at auction a complete cmmg 22 wasp upper. The problem is that the firing pin barely makes contact with the rear of the shell. I took the firing pin out and it seems ok. However I have nothing to compare it to. After charging the bolt it appears to also go all the way forward. Any tips for me ?. Thanx

February 17, 2018, 07:01 AM	#2
brasscollector Senior Member Join Date: July 26, 2015 Posts: 526	Clean out the bolt really good. Mine was doing the same thing about a week ago. I cleaned the firing pin channel out and put a dab of oil in it. Did the firing pin return spring come out with the firing pin? If not, I would say it's dirty in there. Make sure there isn't a build up of carbon at the breach end of the barrel where the collar slides over. I bought mine from a friend and he put over 1K rounds through it. He was always complaining about how it would coke up n quit while his 10/22 would go forever without cleaning. __________________ He may look dumb, but that's just a disguise. -Charlie Daniels

February 17, 2018, 05:36 PM	#3
marine6680 Senior Member Join Date: July 24, 2012 Location: Parker, CO Posts: 4,594	Clean it well... If that isn't the problem... If they did like Ruger and made the firing pin in a way that prevent it from impacting the barrel breech face, then it could be out of spec. Ruger uses a slot that a roll pin rides in. The pin prevents the firing pin from moving too far forward. It may be similar on yours. You may be able to tweak it if need be.

February 18, 2018, 04:46 AM	#5
marine6680 Senior Member Join Date: July 24, 2012 Location: Parker, CO Posts: 4,594	That's true... I was just working under the assumption of there being an actual issue with failure to fire. If not, then there is no problem.

February 18, 2018, 01:23 PM	#6
larson1385 Junior Member Join Date: July 14, 2014 Posts: 11	Thanx folks. I took the bolt completely apart and scrubbed it with some carb cleaner and some very small brushes I grabbed at a gun show. I lubed it up and will head for the range. Live long and prosper.