Popping Primers RRA R3

[Mossy Man]

this is the upper in question:

http://rockriverarms.com/index.cfm?fuseaction=category.display&category_id=567

It's built on a Spikes lower, Spikes LPK, DPMS A2 buffer, Receiver Extension, and Spring.

We were getting popped primers that caused the rifle to lock up (the primers kept successive rounds from going into battery.

Also noticed that getting them to lock back from the last shot didn't always happen.

We were using what appeared to be old Canadian? Milsurp 5.56 that came in little green pouches.

Is it the ammo, or something wrong with the rifle?

[highpower790]

If ammo is mil surp ,chances are ammo is fine but im willing to bet the headspace is off.

[Mossy Man]

whoops...mods can you move this to centerfire?

my mistake

[bubbapug1]

Most likely an ammo or primer issue. Try the ammo in another gun. If it follows the ammo you have your answer.