BCG fires out of battery?

[Belisarius]

ar15 in .223, aim surplus $120 bcg, have had it for 3 years.
First, out of nowhere I got a slam fire. No firing pin indentation on the primer. Same load ever since I got the ar.
Next thing, I got a case head separation, out of nowhere! And again! The trigger slap killed my finger. Blew out a mag release and a magazine, upper and lower intact.
Because I had that feeling, I swapped the bcg with my .300blk, and yes, no issues at all.
Well, then I fired the .300blk, my trigger finger is dead. I haven't been slapped like that since last week when my wife asked me about her weight.
Anyways, for 3 years everything is perfect and then a sudden change.
Any thoughts?
Thank you!!!

 

[CCRBUM]

Maybe headspace issue? Or throat erosion?

 

[srt-4_uk]

Assuming you were shooting reloads?

 

[Scotts556]

Well case head separations happen while the bolt is in battery.

 

[Scotts556]

Assuming you were shooting reloads?

Shit ones it seems.

 

[bfoosh006]

Make sure there is nothing "binding" the FP and FP channel in the suspect bolt.

Also double check the various parts, FP retaining pin, cam pin, FP etc for wear or possible cracks.

And it is possible your brass is wore out or brittle from constant resizing.

 

[hlee]

Primers not seated far enough...

 

[oldfatguy]

Same lower? Firing out of battery and extreme trigger slap? How many rounds fired with that lower? Maybe the problem is in the FCG.

OFG

 

[Belisarius]

thank you everyone!!!

 

[shoot4fun]

Deep clean the bolt carrier; as in carbon scraper and ultrasonic cleaning?
Scrape the carbon off the back of the bolt?
Inspect closely for excessive wear on the carrier?
It does seem like the common part to trouble is the BCG.

 

[db2000]

start over

Geissele Automatics M4A1 5.56 Bolt Carrier Group

DetailsThe bolt carrier group is an important component of any rifle or build, so why would you get something less than the best? The Geissele Automatics M4A1 bolt carrier group is built by a Tier 1 supplier for the Department of Defense and built on the same line as BCGs in use by the military...

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[XTCBoltAction]

Wait. No firing pin indent on the primer? How does the round go bang without an indent?

Also, what does 'finger slap' mean? I'm just not familiar with that term?

 

[Belisarius]

trigger slap is a hard trigger reset that hits back your trigger finger
I'm guessing the primer cup is too soft and the bolt face hitting it is enough
It happened only after I started using remington 7.5 bench rest primers

 

[srt-4_uk]

It happened only after I started using remington 7.5 bench rest primers

Case closed

 

[Gunfighter14e2]

Wait. No firing pin indent on the primer? How does the round go bang without an indent?

Simple the Primer is not seated properly. Common issue with improper reloads. Trigger slap comes from the hammer not fully seated when she goes bang.

 

[XTCBoltAction]

I'm still not getting it. Doesn't a primer need a good indent to ignite?

 

[Gunfighter14e2]

I'm still not getting it. Doesn't a primer need a good indent to ignite?

Not at all, all that has to happen is for the hammer to hit the anvil. With full protective gear on place a primer onto a hard surface an hit it with a hammer. The yellow cake that's in the primer is shock sensitive, you can remove the cake an hit it with a hammer an it will go off as well w/o being in the primer, same as striking the old style strike any where match. In fact 57 old style match heads in a 7.62X51 case would push a 147 gr FMJBT to 2000FPS out of a M14,...BTDT

 

[XTCBoltAction]

How about that!

Now that I think about it, that's why we wear eye protection when priming cases. Duh.

Thanks

 

[srt-4_uk]

Not at all, all that has to happen is for the hammer to hit the anvil. With full protective gear on place a primer onto a hard surface an hit it with a hammer.

Suck a primer up in a vacuum cleaner and it will go off. Ask me how I know....

 

[Charger442]

start over

Geissele Automatics M4A1 5.56 Bolt Carrier Group

DetailsThe bolt carrier group is an important component of any rifle or build, so why would you get something less than the best? The Geissele Automatics M4A1 bolt carrier group is built by a Tier 1 supplier for the Department of Defense and built on the same line as BCGs in use by the military...

www.primaryarms.com

i got two of these yesterday. what a good price. $31 off a piece, so thats why i bought two.... the shelf life on these is incredible.