Cause of primer cap blowing out?????

[rareair]

Went to the range earlier this evening. I've never had this happen to me after firing over 5k rounds on various firearms. But tonight, it happened 7 times.

What I first thought was a dbl feed problem, wasn't. The primer cap was being dislodged from the shell casing during ejection. The case would eject but the primer cap was left in the chamber causing the next round to lodge itself onto the feed ramp. This happened to 3 different rifles tonight. I've got to believe this is a bad batch of Federal XM193 ammo.

What causes this to happen?

[Divernhunter]

Usually overpressure or loose primer pocket.

[elSquid]

5.56 in a .223 chamber.

FWIW... http://www.m-guns.com/tools.php

"5.56 Reamer"

-- Michael

[rareair]

5.56 in a .223 chamber.

FWIW... http://www.m-guns.com/tools.php

"5.56 Reamer"

-- Michael

All my barrels are marked "5.56"

[Timberwolf]

You're more than likely getting pressure spikes. Sounds like the ammo is a little hot. Try a different batch of ammo and see if the same thing happens. If it does strip and clean the rifle very good. Sometimes a dirty chamber/bore will give spikes.