Shooter's Gun Jammed During Aurora Attack, Official Says

[Atypical Liberal]

5. This expert is not surprised.

I'm an expert, and I'm not surprised. The same thing happened to Loughner. Using aftermarket magazines is always a crap-shoot. Using extended magazines is really a crap shoot.

The problem is that a long stack-up of bullets naturally requires a spring mechanism with a long travel in order to be able to provide constant, uniform pressure to feed every round from the first to the last, without being too strong on the first round and too weak on the last. It's tricky.

http://en.wikipedia.org/wiki/Beta_C-Mag

"A test in 2003 by US Army soldiers in Afghanistan found the C-Mag unreliable in simulated combat conditions, with frequent failures to feed among the issues.[4] The Beta C-Mag is not in widespread use by US military forces, and has not been type-classified."