Sorry, I assumed all were trying it with a whole magazineful.

Mag spring tensions seems to effect rim slip under the extractor, too. Some guns may feed some rounds better than others depending on which side of the mag box they are feeding from and depending on where they sit in the stack.

Interesting to me that the "poorest-made" gun, my sons' 03A3 Springfield, with its crude finishing and obvious mass-production external QC, is the most dead reliable gun we have. It is absolutely positve, with a click as the rounds slip under the extractor and no amount of shaking, jiggling or herky-jerky bolt operation can prevent a solid feed.

I've been trying lots of guns with this test lately and there aren't many I can't make hick-up. I've gotten good at making a Mauser jam.

But that rascally Springfield just defies my efforts!!