Hello, I need your expertise... I have a First Generation Sig Sauer MCX with 11.5 inch barrel fitted with a Advanced Armament M4-2000 suppressor. Went to the range yesterday and fired 100 rounds of American Eagle 5.56, 55 grain FMJ. Out of 100 rounds 29 rounds were light primer strikes. When I pulled the trigger I would get a click but no bang.

My question: Can a suppressor cause light primer strikes?

Looking forward to your responses.

Thanks.

quote:

Originally posted by Chopper*Pilot:
Can a suppressor cause light primer strikes?

I cannot imaging a situation where a can could effect primer strikes. You should look elsewhere.

Has the MCX done this before, either with this ammo or another type?
Is the MCX new or old? High round count? Have you recently cleaned or lubed it?
Does this ammo have issues with other rifles?

^^^Agreed, not the can as it had nothing to do with the firing pin striking the primer.

Sounds to me like you had some bad rounds. I'd try different ammo to see if it still happens. If not then you know what the problem was.

Are you using the stock trigger?

quote:

Originally posted by fritz:

quote:

Originally posted by Chopper*Pilot:
Can a suppressor cause light primer strikes?

I cannot imaging a situation where a can could effect primer strikes. You should look elsewhere.

Has the MCX done this before, either with this ammo or another type?
Is the MCX new or old? High round count? Have you recently cleaned or lubed it?
Does this ammo have issues with other rifles?

It's a first generation MCX just over 500 rounds unsuppressed and about 200 rounds suppressed.

quote:

Originally posted by DaBigBR:
Are you using the stock trigger?

Yes, stock trigger.

I sent the MCX back to Sig letting them know I was getting light primer strikes. The operating rod spring clip was broken. So, they replaced it.

Once I got the MCX back from Sig I went to the range again. Same problem, light primer strikes, also the spring clip broke again. It also appears that operating rod is striking the back of the lower receiver and causing damage. This is causing the spring clip to break.

It's off to Sig again.

While the MPX is not the same as the MCX, both use a bolt carrier, a rotating bolt and a movable firing pin.

A friend asked me to look at his MPX which was failing to hit the primer hard enough at random. I found the firing pin channel was plugged with black gunk which prevented the firing pin from fully going forward to hit the primer. Actually I had taken it apart expecting to find the firing pin broken like what happened to my MPX. Soaking the inside of the bolt in solvent and then flushing it out restored proper firing pin operation.

I wonder if your firing pin channel is gunked up?

Thanks for the information. I will certainly check that when I get it back from Sig.