The Serbu SN-50 is an odd gun: a single-shot .50 BMG that you have to kinda disassemble to reload. It’s little more than an M2 machine gun barrel with some modifications; that makes it less expensive ($1259 rather than the seven-plus grand you can expect for semi-auto .50s), but is seems like a lot of bother to go to between each shot. Still, Serbu has a good reputation and the design seems pretty rugged. Yet… one of them underwent rapid unplanned disassembly right in the shooters face, doing him a lot of bad damage. The firearms side of YouTube has taken notice and lots of people are trying to figure it out.
Yow.
This guy focuses on the rather unique ammo, as well as unfortunate design features:
Same guy revisits the issue, and is rather more explicit in his opinion that the RN 50 is not a weapon to be fired:
Forgotten Weapons covers the topic of firearms exploding:
Mark Serbu made a comment:
Serbu may, depending on the results of the analysis of the rifle, be in a spot of trouble.