An ARFCOM readers S&W M&P15T suffered an incredible catastrophic failure, probably the worst I have seen.

NVCapCop reports …

My S&W M&P15T was destroyed today with an epic Kaboom (catastrophic failure).

I did not suffer any major physical injuries – received a welt on my left bicep (MagPul AFG hold) that looks like a bad bug bite or bee sting from shrapnel impacting my skin. A tiny little cut on the left forearm as well as lots of tiny red dots on inner side of elbow. The injuries felt kind of like a rug burn a few hours after the event.

Cartridge #45 out of the first 50 round box. USAammo 223 55 gr FMJ Lot #2906113.

The ammo was recently purchased USAammo, remanufactured on once fired LC brass. As you can see from the pics, the usual parts suffered catastrophic damage. The Troy quadrail seems to have helped keep the upper receiver from completely coming apart.

The destruction: Both sides of S&W factory upper assembly, the dustcover, both front corners of the magwell, hairline fractures directly under the left and right sides of the picatinny rail, cracked barrel extension in the middle of the feedramp, factory lower bulged on the bolt catch side. The PSA MPI bolt, the Failzero bolt carrier, and the PMag were completely damaged also.

Possible damage: BCM vltor gunfighter CH, RRA 2 stage trigger/hammer, pivot pins.

…

Update 7/26/11: Spoke to the CEO this a.m. He is eager to investigate the ammo lots so KBs don’t happen to other purchasers. He admitted that some of his ammo has been overpressured due to “Western” powder supplier using powders with faster burn rates. The overpressure would also explain why my buddy had so many stuck cases of .308 175 gr. match ammo in his ArmaLite AR-10.

[ Many thanks to Nathan for emailing me the link. ]