223 case rims

bryan6842003

I was loading some .223 rounds this weekend when I noticed something new to me. I usually reload pistol, but I am new to rifle.
I was having some problems with cases being stuborn going into the shellholder on some cases. I didnt think much of it at the time, but as I got to the last process I was using a lyman headspace gauge to check the rounds and they were not seating into the gauge all the way. The rims were what was keeping them from seating.

What causes this? Would it hurt anything to trim the sides of the cases back down so they will seat?

I have bought and picked up a lot of used brass, so none of this stuff is coming from anything I am doing.
Thanks!

dcs shooters

I've run into the same thing. I think the extractor hitting the rim when chambering the round is mushing it out.

243winxb

The rims can be filed/turned down where the extractor has made a ding. Do not file the case body. Makes sure primer pockets are tight & that the web area has not expanded from a to hot loading.

bryan6842003

Thanks for your input. I have shaved some of them down and going to try them.
It seems to be more on Lake City brass, but I assume they have the same dimensions as .223.
I guess since this is range brass someone could have loaded them too hot, but they dont seem to show any signs of extractor damage.

victorj19

I ran into that when I bought 1000 rounds of mixed, once fired 223/5.56 brass. Haven't tried the others yet but the Lake City brass had a fair percentage that were difficult getting into and out of shellholders (two for press and one for hand primer). Decided to just recycle them.