I purchased some once fired lake city brass and have finally gotten around to processing it. It looks to be good brass but looks can be deceiving. During the resizing process several cases did not go all the way into my case gauge and what I men is the rim of the case would not sit flsuh or right below flush. Some of them you could gently push and the case would go all the way. I checked my sizing die and all is good and not all of the cases do this. Do you guys have any ideas as to what may be causing this? All of the cases still have the primer crimps.

Thank you

I'm gonna guess that brass was first fired through a submachine gun. Should be ok.

What Dave said. Loose chambers on those guns can make brass difficult to size.

LC brass is good quality stuff if you can make it work

You said checked sizing die , but did not say if you tried to resize then again, some times this works for me

Are you using a small base resizer?

Yeah small base die can help but alot of times it's Nick's and burs on case rim.
Pretty common in brass fired out of semi autos.most of the time they'll run fine in your weapon
Pretty common thing in once fired brass of unknown source.get extractor and ejector marks that screw up case head but sometimes a small base die is needed to slightly under size them to drop in gauge

In 9mm and 45 I cull those brass.ill label them as tight in gauge so they are range only ammo
You could separate the 223 in the same way if a small base die doesn't fix the problem.alot of times those culled rounds drop right into gauge and can be reloaded again and drop into gauge but those 223 that fit tight always go bang but try to chamber a few first.should be no prob but don't want an out of battery round going off.if they don't chamber you know you need a small base die

I am not using a small base die but have thought about getting one. I can take a small file and lightly brush the case rim and it will fit into the gauge. Maybe I need to invest in a small base sizing die.

Thank you

If all you have to do is lightly push them into gauge they should be fine.most likely burs on case rim
But it never hurts to have a small base die at some point you'll need one shooting once fired brass

Also can do a plunk test with those rounds in all your 223's that's better than any gauge

I tried closing the bolt on several of these last night and they the bolt locked up without any undue resistance and the case ejected fine. I also did a check someone recommended on another site where you flip the case around to see if it will fit into the gauge, the sampling I did last night worked fine. this is really baffling

Just remember some gauges are minimum spec and some are maximum.if your life depends on the ammo use the ones that plunk the gauge if not use as range ammo.ive dealt with same situation and they always fire without hiccups.i didn't have a gauge for a long time and never had a single jam.like others said could have been fired out of a saw m249 with generous chamber but mostly it's nicks on case rim.dont sweat it

For me a gauge just lets me know it's in factory spec and I'm not oversizing more than necessary.some of the brass gets stepped on or beat up by extractors.223 brass is so cheap you could cull them if it bothers you enough.hard to make brass perfect sometimes fired out of who knows what .it's very common I promise it's not just you.lol

Even after small base sized with die turned all the way down to touch shell holder they don't always drop down flush

Thanks for all of the help. I am going to separate these from the rest for now.

Fired in a machine gun chunk them not worth the trouble

I've loaded tons of it.it will run fine.small base die comes into play when fired in machine gun or you've got a tight chamber.