AR blowup

[RED DIRT]

Title is
AR BLOWUP

Yup, i see that now, lol. See what happens when you get old????

 

[RED DIRT]

Glad to see the OP got this figured out, and learned a very valuable lesson. "Trust, but Verify"
Glad to know he wasn`t hurt beyond what had happened. It could have been MUCH worse.

I was a member of a club where most people reload. There was a trap shoot one evening, 5 people standing, one guy shot his stage, first round, BOOM, gun blew up, the guy to his left fell down. A piece of the shotgun that blew, went right through the guys neck, killed him before he even hit the ground. This can happen to anyone who reloads. Be very careful guys. Check your work, several times. And NEVER use someone else`s reloads!

 

[jelenko]

clearly see that these gauges are not meant for semi-autos.

That's not exactly what Brownells tech said.
Their point was you wouldn't get consistent measurements if you let the bolt slam home.
It would work if you ease bolt bolt closed.

 

[Turbulent Turtle]

Yun

That’s the worst thing to do on an ar
If there’s any slop in the bolt , or in the hammer / bolt carrier safety clearance , you will get an out of battery shot
But more than likely just a bunch of misfires from the bolt not fully closed
Always release the bolt on an AR, or any semi auto, but make sure there’s a mag in it. I know a few people who didn’t and had slam fires with AR 15 and 10’s floating firing pin
The follower slows it down enough

Unlike the AR-15, the AR-10's firing pin is not floating, there is a spring with the firing pin.

 

[akajun]

Yun

Unlike the AR-15, the AR-10's firing pin is not floating, there is a spring with the firing pin.

what brand? my DPMS pattern guns dont.

 

[Rocketvapor]

 

[Turbulent Turtle]

what brand? my DPMS pattern guns dont.

Only Armalite makes AR-10s.

 

[akajun]

Only Armalite makes AR-10s.

 

[akajun]

Ok Mr technically right
However after you gave us all a lesson in minutia and terminology, explain to us how that has any affect on the need to put a nag in when closing the bolt on a round in slow fire and out of battery detonation

 

[Turbulent Turtle]

Ok Mr technically right
However after you gave us all a lesson in minutia and terminology, explain to us how that has any affect on the need to put a nag in when closing the bolt on a round in slow fire and out of battery detonation

The AR-10 was designed with a spring for the firing pin and there was a good reason for that. I don't know what a DPMS is but I'm guessing it's a cheap knock off of an Armalite AR-10 and they cut too many corners.

 

[dhagerty40]

The AR-10 was designed with a spring for the firing pin and there was a good reason for that. I don't know what a DPMS is but I'm guessing it's a cheap knock off of an Armalite AR-10 and they cut too many corners.

you really need to read this blog:

AR10 Vs LR308 - What Is The Difference? | The Primary Source | The Primary Source On PrimaryArms.com

Our guide on AR10 platforms versus LR308 platforms covers compatibility and differences between the two, which are too often incorrectly referred to as the same rifle.

blog.primaryarms.com

 

[divingin]

Too long brass was the only obvious problem. Other than the blown up rifles of course. I was thankful I didn't get hurt.

No, not the only obvious problem. Varying charge weights, along with mixed brass, inconsistent lengths; there's lots of stuff that could stack in the wrong direction and cause problems. You're just looking for a simple answer, which may or may not be the root cause.

 

[jelenko]

Varying charge weights

The 1.6 grains variance would seem to be 'impossible' => something way out of whack.

 

[karrarararararar]

The 1.6 grains variance would seem to be 'impossible' => something way out of whack.

Wonder if it's similar to an issue I had years ago. I had issues with variance throwing charges with my Hornady measure. Turns out the micrometer insert I added to it had a horrible fit and would move around. Swapped back to the standard insert and the problem went away.

 

[papa]

I wonder if something besides the firing pin struck the primer.

An AR-15 firing pin cannot reach the primer until the bolt fully cams into the locked position, and I am pretty sure it is the same on an AR-10.

Not true. I had 3 slam fires on an ar15 using cci400 primers. I do believe the primers were sitting slightly high.

 

[jelenko]

Not true. I had 3 slam fires on an ar15 using cci400 primers. I do believe the primers were sitting slightly high.

I think you misunderstood SecondsCount. A slam fire is exactly what he described.
I think his post was talking about whether the firing pin could hit the primer while the bolt was out of battery. A slam fire happens when the bolt is in battery and the firing pin strikes the primer hard enough to ignite it.