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erik_26
02-18-2012, 8:13 PM
I may or may not be having issues with my Bolt Carrier Group.

I have a Bushmaster upper along and factory BCG. When loaded with Lake City ammo I get a fail to fire every 10-15 rounds. There is a primer strike. But the round wont fire. A friend of mine loaded the failed to fire rounds into his Noveske and all rounds fired for him.

Ideas?

mod1217
02-18-2012, 8:20 PM
Have you tried diff ammo? It may be a weak hammer spring not really a BCG issue... And in my experience light strike ammo usually always fires the second time around except if the ammo is completely bad

bender152
02-18-2012, 8:21 PM
How many rounds have been fired on the BCG? You could try replacing the firing pin.

Ding126
02-18-2012, 8:25 PM
Is your bolt nice n wet? Bushmasters seem to have really tight BCG and need a little break in time and plenty of lube..That's been my experience with 3 rifles.

erik_26
02-18-2012, 8:27 PM
Have you tried diff ammo? It may be a weak hammer spring not really a BCG issue... And in my experience light strike ammo usually always fires the second time around except if the ammo is completely bad

No issues with Remmington, Federal, American Eagle.

I tried to fired them in my AR 2-3-4 times. My friend would pop them in his after that and they would fire for him first try.

How many rounds have been fired on the BCG? You could try replacing the firing pin.

I only have ~1000-1500 round through it.

mod1217
02-18-2012, 8:41 PM
If you fire the misfire round through you rifle that many times and have 1000-1500 rounds through it then check bender's post, check the firing pin

bender152
02-18-2012, 8:46 PM
Did this problem just start happening? A firing pin normally should not need to be replaced so soon.

mod1217
02-18-2012, 8:52 PM
Did this problem just start happening? A firing pin normally should not need to be replaced so soon.

But he said he tried the light strike ammo 2 3 4 times and still it wont fire, and soon as he let his friend load the same ammo it fires immedietly then I'm thinking the firing pin is off-specs to begin with.

I dont know if it can be done or the Noveske firing pin is completely diff but you can try to put your friends firing pin on your bcg to see if that fix your problem

Arkangel
02-18-2012, 9:07 PM
It sounds like a weak hammer spring. Lake city ammo uses hard primers. Easy and free way to tell weather its bcg or hammer spring related is to swap lowers with your buddy. If it goes bang, its your hammer spring.

ejhc11
02-18-2012, 10:18 PM
It sounds like a weak hammer spring. Lake city ammo uses hard primers. Easy and free way to tell weather its bcg or hammer spring related is to swap lowers with your buddy. If it goes bang, its your hammer spring.

+1
I would do that - is the lower factory build or a assembled yourself.

Ziggy91
02-18-2012, 10:59 PM
I agree with others... sounds like the hammer spring. I've been getting same thing maybe once or twice per 100 rounds since I changed my trigger setup. BTW, I'm also using 5.56.

Mail Clerk
02-19-2012, 9:22 AM
I may or may not be having issues with my Bolt Carrier Group.

I have a Bushmaster upper along and factory BCG. When loaded with Lake City ammo I get a fail to fire every 10-15 rounds. There is a primer strike. But the round wont fire. A friend of mine loaded the failed to fire rounds into his Noveske and all rounds fired for him.

Ideas?

erik_26,

Off the top of my head you might check the primer dents. If they're shallow I'd check to see how deep the rpimers were seated. They may be just a hair too deep. Next check to see if your firing pin is not fouled too much so it won't freely move about in your bolt carrier. If that checks out then go to your hammer spring and see if it may be too weak.

If all that checks out then I would suspect the bullet primers might be too hard or it's depth seating.

Good luck,

Mail Clerk:oji:

CHS
02-19-2012, 10:25 AM
What lower? Did you build it yourself?

MAKE SURE that the hammer spring is not installed backwards. It will lead to a weaker hammer strike that might not always set off military primers.

Check that before just replacing the spring.

The hammer spring legs, when properly installed, should be perfectly parallel to the ground when resting on top of the trigger pin. They should be coming from the BOTTOM of the hammer pin area. If they are coming from the top, they will be at a downward angle to rest on the trigger pin and that means the spring is BACKWARDS.

Takes 30 seconds to check and fix.

Pay very close attention:
http://i.imgur.com/IxPV6.gif