size/trim or trim then size


January 7, 2008, 09:18 PM
just wondering if you trim then size wouldn't it stretch the case when you size it? I read on another post on here that you trim the case then size/deprime. just want to get it right thanks

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January 7, 2008, 09:23 PM
I'm new to this, but I just read in the "ABC's of Reloading" that you always trim AFTER resizing because the case does change shapes.

January 7, 2008, 09:32 PM
sizing on bottle neck cartridges sets the shoulder back,and sometimes the expander ball will pull it back out a tad,so trim then size.

January 7, 2008, 09:33 PM
Yep Size then Trim

The only twist on this is what some guys are saying about RCBS X-dies.

For normal situations size, then trim,

January 7, 2008, 09:45 PM
Good, thats what I started doing, Size/decap then ream primer pocket then trim then retumble. thanks guys

January 7, 2008, 10:43 PM

After a little research tonight while replying to this thread ( I discovered that there has been contradicting information published in Speer and possibly other manuals. According to my Speer manuals 9 and 10 it clearly states that Step one is clean, inspect and Trim before Step 2, Resize. However, my Sierra and Hornady manuals instruct you to Resize then Trim. The Sierra manual even comments what <SLV> stated that the case length will change when resized.

I learned to reload back in the early 70's with Speer manual and I so I have always trimmed and then resized and to my knowledge has never been a problem. In the past before I used X-Dies I would sometime forget to measure my case length until after I resized. If I had to trim after it was resized, with an RCBS case trimmer, it would be very difficult to get the pilot into the case so I would resize it again just to ensure I had good neck tension for calibers like .222 and .22-250 that I don't crimp. Now that I use the RCBS X-Die for .223 I don't think it makes a difference, but since I only neck resize my other rifle cartridges I going to do some checking to see if really does make a difference- the jury is out on this one for now.

January 8, 2008, 12:52 AM
Take a fired case, measure it for length. Now run that case through the FL sizer. Measure it again. IF you set the shoulder back it will be shorter. Sometimes it will be a lot shorter. If you trimmed BEFORE sizing, you now have a case that's too short. If, on the other hand, you failed to lubricate the inside of the neck, the expander button will pull the neck forward.

ALWAYS trim AFTER sizing. There's just no way of knowing how much the sizing operation will change the OAL of the case.

January 8, 2008, 07:25 AM
Size, Neck Size then Trim to length.

January 8, 2008, 09:43 AM
Lyman and Lee manuals both say SIZE then TRIM.

January 8, 2008, 10:13 AM
If you trim before you size, you will have varying OAL's after you size the brass. Always size, then trim.


The Bushmaster
January 8, 2008, 11:21 AM
Clean, Resize/decap then trim the case to length...

January 8, 2008, 04:10 PM
Nobody has mentioned it yet, but the case trimmer pilots are made to perfectly fit a sized case neck.

They are a sloppy loose fit in a fired case, and chattering, and uneven cuts will result if you trim using a loose fitting pilot on an unsized.

That ought to answer the question on when to do it right there!

January 8, 2008, 04:42 PM
Yeh, you are not going to stick a unsized case neck in a Gracey or Giruad trimmer. You have to size first.

January 8, 2008, 11:38 PM
Thanks guy, There were some posts I saw in another topic that didn't make sense to me . just want to make sure

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