Rock River Arms Mid Length Carbine Kaboom!

I was standing next to a shooter that experienced a catastrophic failure.  The details I share were reported to me by the shooter, the gun was a factory RRA mid length gun and the ammunition used was Ultramax remanufactured (see box in picture below).

The incident occurred during the last string of fire.  The previous 45-rounds were mostly uneventful, with the exception of what appeared to be a couple of underpowered rounds.  This appears to be an ammunition related event.

The bolt carrier appears to have split, you will notice it protruding into the magazine well.  On the left side the upper was cracked and bulged, the bolt hold-open sheared off.  On the right, the upper bulged and the ejection port cover bent.  The magazine was blown out of the rifle.  Notice how the bottom of the mag bulged from the pressure.

Thankfully no one was hurt.  I think that is a testament to the design of the rifle and the quality of RRA.

According to the owner, RRA told him it was caused by the ammunition (Ultramax) and this is the second gun they had destroyed by it.  The RRA mishap report, “Lower OK, bolt still in battery, lockup.  Fired casing came apart at base, no bulges in barrel.” RRA replaced the upper at cost ($323.50) after he signed a release absolving them of any liability.  They suggested contacting the ammunition manufacturer.

All of the guys that shoot with me are experienced; this was an excellent reminder on why you need to wear quality eye protection.  We are happy that no one was injured.

The first pictures were taken on the firing line, the rest at the time it was shipped back (note hand guard change). Thanks to DH!