Overseat primers?

[chamokaneman]

After going through all that, I just can’t imagine the rim’s the problem then unless you’re using some beat up old crap brass.

So let me recap for my own sanity...These are loaded and crimped 9mm rounds that won’t fully drop in a now completely cleaned case gauge but drop perfectly fine in your barrel AND you have in fact fired the offending rounds successfully in your pistol? You’ve got a bad gauge. Edit: that is of course a flawed conclusion. But, try this with your next round that doesn’t fit in gauge...turn the round just a little and try again and then again. I have two gauges Hornady and RCBS. Everything fits the RCBS almost everything fits the Hornady—when it doesn’t, a little turn always works telling me it’s....

I'll try it.

 

[gifbohane]

Tried to sand off the burr by rolling the rim on a piece of light sand paper a tiny bit but didn't seem to make any difference so I press on plunking them in my barrel

Interesting, I tried the same thing and it did not allow the 9mm to seat further in the barrel or gage. Will try the turning the gage trick.