The two cartridges on the left are deeply scalloped and cannot be chambered.
The two on the right are only slightly scuffed. All are LC 04 Lot #70.
The rifle is an Olympic Arms GI-20, this is not my rifle. My Bushmaster will
digest this stuff all day long with no problems. Thanks.

Edited to add: These cartridges did not come from the factory in this condition.
This was caused by chambering them in the rifle.

http://homepage.mac.com/mshadwick/imgs/040823.jpg

The scalloping is caused by insufficient lubrication, improper case sizing, or improper pressure application during the load-up process at the ammo maker.  It -could- be caused by a chambering problem (if you're already tried to chamber it, say) but normally those cause a visible scratch that will show up brighter than the base 'petina' on the cartridge itself.

I would go through the lot and 'weed out' these.  I'd discard them because cartridge internal volume being reduced CAN cause pressure spikes, to say nothing of projectile line-up in your chamber...

The rifle is doing this to the ammo?


If so, the answer is OLYMPIC ARMS are JUNK.

That's all.

Ehh...

I doubt ANY rifle in good working order would do this to ammo but it might.

If it IS the rifle doing it, the first place I'd look is my mags.  Try a 10-round new-production with green follower if you have one around.

Quoted: I doubt ANY rifle in good working order would do this to ammo

RIGHT.  OLY ARMS are not Good working rifles.

Your opinion, to which you are entitled.