Good Morning Gents,

I recently purchased a complete 16" .50 Beowolf upper and mated it with a new DPMS standard lower.  Took it to the range, giddy as a schoolgirl for a little .50 caliber fun.  Slap in a loaded 7 round mag (loaded with Alexander Arms FMJ,) take her off safe, squeeze the trigger...CLICK.

Perform immediate action, eject unfired round, and examine it.  Primer has a "dimple," other than that round looks normal.  I pull the Bolt Carrier Group, do a function sheck, everything looks normal, so I try again...CLICK.  Dimpled primer, nothing more.  

I figured I'd try a different lower, so I tried a different DPMS lower I'd been using with a DPMS .22 upper.  Same results...CLICK.

Tried it with a Bushy lower, same results...CLICK.

I'm frustrated because after years of using the AR platform, this is my first malfunction of any kind.

What's the issue?  Can anyone tell me things to try to get her running again?

Thanks