I am fortunate enough to have some great readers. One of them, Alan, had read Kaboom!!! 300 BLK in 5.56/223 AR-15! and shared that he had experienced a similar incident shortly before I published that post. Alan was kind enough to send me his damaged parts to photograph and share.
My understanding is another shooter was using this rifle at the range and accidentally picked up a magazine with 125 grain 300 BLK ammunition in it. The parts shown in these photos were damaged and thankfully, no one was hurt.
This first image shows the majority of the damage. The upper receiver and the bolt carrier both split. The magazine deformed at the bottom, which is similar to most other catastrophic failures we’ve seen with AR-15s.
The extractor was bent and damaged. The tab that retains it, cut through the pin.
Note the damage to the rear surfaces of the bolt.
The barrel extension cracked along its length, in line with one of the feed ramps.
Another view of the cracked barrel extension.
The right side of the bolt carrier split off.
The upper receiver was deformed and showed evidence of cracking in multiple locations.
The left side of the upper receiver near the barrel-nut threads began to crack and separate.
The rear lug of the upper receiver was cracked and began to separate.
This is the section of the barrel where the 30 caliber projectile was lodged. There was no external deformation in the barrel. The outside diameter was within .001″ of the rest of the barrel.
The 30 caliber bullet was fire formed to 22 caliber. It was simply removed with a cleaning rod.
The fire formed projectile and ruptured 300 BLK case.
All things considered, this Wilson Combat barrel handled this event fairly well.
I’m glad no one was hurt. Alan, thanks for sharing! For more discussion of the 300 BLK in 223 and 5.56mm rifles, see Kaboom!!! 300 BLK in 5.56/223 AR-15!.