.223 cases not straight?

[cobber]

Not quite sure how to phrase this. I am trimming .223 brass for reloading, using a chuck in a cordless drill. Once in awhile I will lock in a case for trimming, and it's obviously not centered along the axis of the chuck/drill, but instead gyrates. If I actually manage to trim the case, it invariably comes up short and/or lopsided.

Is this my imagination, or is some brass actually off-center? I'll see if I can add a video later...

 

[straight-shooter]

Probably not off center but more likely the rim is bent from hitting a hard surface after being ejected or the ejector itself has damaged the rim. Just a guess without actually seeing it.

 

[throttletony]

check the rim/lip -- I have some 223 cases that seem like they were extracted really hard, and it bent the rim.
I also use a drill to trim to length (the Lee setup), and bent rims give inconsistent results. Otherwise I'm happy with the Lee case trimmer.

 

[cobber]

Thanks. I'll try to make a video. It's kind of amusing to watch this stuff wobbling.

 

[oldpink]

Have to agree that it's likely a distorted rim.
Dunno if you have a conventional benchtop trimmer, but maybe you could see if the wobble is there with that, too.
If it's not, I would point the finger at the drill chuck.

 

[throttletony]

p.s. for any cases that I think might have bent rims, I set the case on a flat surface (standing upright) and check for wobble.

 

[Leo]

It seems like you are using a LEE trimmer kit. That narrow shellholder ring is difficult to get tight if there are burrs on the case rim. It is a lot more money, but Sinclair International makes a hex drive adapter and shell holder that is much larger in diameter and clamps the brass way better.

It is a good idea to do your case trimming after sizing. You might experiment and take your cases that wobble through the full length sizer again. For bottle neck brass that I shoot in matches where I am really counting score, I size the brass, rotate it a third of a turn and size it again. When I check for concentricity on V blocks with a dial indicator riding the bullet major diameter, the double sized brass is generally .0005 to .0015" more concentric. That probably does not make any difference 99 percent of the time. Since I am a bit OCD, It makes me feel better, and that finds extra points on the score sheet.