Home Forums Hunting & Shooting AR and Tactical Rifles Bushmaster ar-15 blow up

Dad bought a new BM 223 2 months ago and has had about 100 rounds of new fmj 223 ammo through it. This past weekend while shooting at a coyote, on the third shot the rifle exhausted out the clip blowing it apart. The bolt is froze in the closed position and we cant get it open to verify that it's unloaded. Has anyone heard of this problem? It was very loud and scared us both badly. No injury happened thank God. How do I go about sending it back? I assume I will have to take it to a GS to see if they can atleast get the bolt back and the spent, or hot case out. Any thoughts??? Thanks

What brand and type of ammo?

Call BM a call and see what they say to do.
Yes this has happened before and every instance I've read about, the ammo company winds up paying the bill.

My theory is bullet setback, since the AR cannot fire out of battery, it's physically impossible and standard rifle powders won't allow a double charge. But there are other theories as well.

Oh and the case in the chamber will more than likely be the fired case, too much going on to cycle the action.

He was shooting HSM FMJ ammo from the hunting shack in Stevensville, Mt.

Just saw one of these last week. I think it was HSM ammo, except the owner slipped a .300 blackout case in there!

The .308 cal. bullet swaged down to .224, but was really long, and jammed in the barrel. Got everything apart with some big hammers! Looks pretty rough, with lots of breakage.

Turns out is was not an HSM Ammo issue in this case!

Good luck!

We had some HSM kaboom an M&P15 a year or so ago.

Contact HSM as well, document everything with pictures and even notarized statements.

Use a cleaning rod from the muzzle to check if there is a loaded round in it.

My correction. It's was BVAC ammo that he was using.

It was a bushmaster he was using.

A number of years ago, a shooter did similar with a 300 whisper in an AR. The barrel maker sent in photo's of the projectile which he was able to hydraulically remove. Said the barrel was still good as new once cleared and the shooter had created the first 168gr, .224 bullet. Don't recall what happened to the rest of the gun

Local walmart had a bunch of Remington .223's with 50 grain HP's that weren't moving (most of the guys using .223 around here use them for coyotes or deer) and had them on sale for less than new brass prices. I bought all they had with the intention of plinking to empty the brass, then reload with my regular loads. At some point I ejected an unfired round from the AR I was using and that 50 grain HP was very noticeably pushed back into the case neck. I manually cycled a few more and about every third or fourth one would do it. From then on I only shot them in my bolt gun.

Should I own a 300 BO I will buy red tape to put on the magazines!

All my 300 BO brass will be Nickel plated.

What is this so-called "bullet setback"? How does it create enough extra pressure to create a kaboom situation?

Loose neck tension, bullet hits feed ramp, drops the ogive below the case neck, pressure rises substantially.

I realize this is factory ammo but this just reinforces my belief that if you are using reloads in an AR, you should crimp the bullet in the case.
kwg

It's called bullet set back. I highly suggest you crimp any reloads especially if you are putting rounds in a long magazine. kwg

You got more than a couple of reloaders on this forum that don't crimp and don't have bullet set back. You use the proper diameter neck expanding ball and a case full of the proper powder. Problem solved.

Yep, anneal your cases when they need it, full case of powder, proper neck tension and no need to crimp.

If you're not sure, the Lee crimp die can be helpful.

This is bullet setback.