Do those of you who trim your cases, trim before or after resizing? I've never bothered much with trimming but I recently started loading for .45 Long Colt and .454 Casull. When loading for the .45 Colt, I noticed a slight difference between the length of my Starline brass and the length of my Remington brass. Not long ago I purchased a set of Lee case trimmers, one for most of the calibers I reload for. I figured I'd trim the .45 cases so they were a uniform length. The trimmer will not fit into the empty case after the case has been resized. If I trim before I resize, it will work just fine. Seems to me that the case should be trimmed after resizing to be most accurate. Anybody else ever have this problem?

Thanks, Doug

Something I've never checked...sounds like something worth checking. Usually trim them afer sizing, but I'm cheap and make my own pilots so they are made to fit the cases this way.

Maybe i should try a batch each way and see if there is any real differnce.

If you are trimming to SAMMI spec, trim after resizing. If you've done a chamber cast and know how much room your chamber actually has, you can trim before sizing (as big as the case will get in your gun) but the trim length will be determined by your chamber measurements and not to SAMMI trim length, less an allowance for the neck to lengthen when it squirts into the sizing die. Much bother to gain maybe 5 or 10 mils of useable neck length. I can't see an accuracy improvement from it, but I'm not shooting bench rest guns. It is safer and easier to trim after resizing.

I bought Lee trimmers for my pistols twenty-odd years ago and never used them. The cases stayed shorter than the trim length, so they wouldn't cut. It turns out most pistol rounds don't develop enough pressure to stick the case wall to the chamber wall, so they just blow back during firing and don't get stretched.

The Cassul is another story. If you run it up to full pressure it will probably grow like a rifle case and have to be trimmed. If it's brass is too tight after sizing, call Lee and they will be able to make you a sizer that fits.

Nick

Do those of you who trim your cases, trim before or after resizing? I've never bothered much with trimming but I recently started loading for .45 Long Colt and .454 Casull. When loading for the .45 Colt, I noticed a slight difference between the length of my Starline brass and the length of my Remington brass. Not long ago I purchased a set of Lee case trimmers, one for most of the calibers I reload for. I figured I'd trim the .45 cases so they were a uniform length. The trimmer will not fit into the empty case after the case has been resized. If I trim before I resize, it will work just fine. Seems to me that the case should be trimmed after resizing to be most accurate. Anybody else ever have this problem?

Thanks, Doug
I use a bunch Lee trimmers for rifle cartridges and the pilots all fit after resizing. I wonder if something is wrong with yours? I'd call Lee and ask them.

Thanks for the info guys. This afternoon after posting my question, I got frustrated with the darned thing and took it to some very fine sandpaper. After working on it for about 15 minutes, I took a rag with some flitz on it and polished for another 10 minutes or so. Now it just fits inside the resized case. I didn't want to remove too much material.

Have always heard you want to measure AFTER sizing, as the case will be at maximum length after this process. That's the way mine are measured to check on length, anyway.

Have always heard you want to resize AFTER sizing, as the case will be at maximum length after this process. That's the way mine are measured to check on length, anyway.

It does seem to be the logical way of doing things, doesn't it? Thanks for the reply kdub, now that I've got my problem fixed, I'll be able to to do things the logical way. :cool:

Had the same identical problem with the Lee trimmer and my .357 cases. Ended up running them part way up into the neck expanding die to get the trimmer pilot to fit. Extra work but it solved the problem. Will now do what you did and polish up the pilot a little. Apparently thr problem is pretty wide spread. Noticed on my new 9mm trimmer from Lee the shoulder of the trimmer pilot is very shallow and had no trouble trimming over 700 cases that had been resized.

Hey, Doug in Alaska -

Just noticed a big boo-boo in my earlier post. Should have said "Measure after sizing" instead of "resize after sizing".

Makes a little more sense this way - was in a hurry last night and let my fingers get ahead of my thinking! :p

We kind of figured it out anyway.

haven't done a full fledged test, but if trimmed evenly before sizing, tend to come out even after sizing, just a little bit longer. How much longer depends on how much it's sized...but being revolver, all taht really counts is tht they are even so they can all recieve the same amount of crimp.

Thanks for the info guys. This afternoon after posting my question, I got frustrated with the darned thing and took it to some very fine sandpaper. After working on it for about 15 minutes, I took a rag with some flitz on it and polished for another 10 minutes or so. Now it just fits inside the resized case. I didn't want to remove too much material.
Doug,
I had the same experience as you with a once fired box of 357 Mag cases one time. I fixed the problem the same way you did. I bought another trimmer and chucked it into my drill press and sanded it down until it would fit the cases. The only thing I could figure is I got a batch of cases that had slightly thicker walls. After going through the sizing die the interior dimensions of the case mouth was a little shy of the normal case dimensions. The next time the cases came through the reloading process the original trimmer would fit. I have never had to use the down sized trimmer since.
Cary

I ALWAYS trim after re-sizing - but I have a Lyman trimmer and the pilot fits perfectly snug this way..

When trimming brand-new brass, I just run each case into the sizer to where it gets snug. This is because case mouths on new brass never seem to be perfectly round.

Doug,
I had the same experience as you with a once fired box of 357 Mag cases one time. I fixed the problem the same way you did. I bought another trimmer and chucked it into my drill press and sanded it down until it would fit the cases. The only thing I could figure is I got a batch of cases that had slightly thicker walls. After going through the sizing die the interior dimensions of the case mouth was a little shy of the normal case dimensions. The next time the cases came through the reloading process the original trimmer would fit. I have never had to use the down sized trimmer since.
Cary

Thanks for the reply Cary! I think I've got it figured out now.

Doug

all taht really counts is tht they are even so they can all recieve the same amount of crimp.

Thats my way of doing this!

Thats my way of doing this!


I really don't sweat 1.56" vs. 1.54"..if I set the trimmer within a couple of 1/100ths of what I was looking for, and all the cases get trimmed to the same length, who cares?

Am likely to just set the trimmer to a new (unfired) case ans trim them all to that length reguardelss of whatever that length measures out to be.

Did you ever check to see if you were resizing too much? This is all too common problem with full length resizing. If it ever happens to you again mic up the inside of the case and check to see how much undersized it really is. This is a real problem with a lot of straight walled pistol and rifle dies.