Reloading Process - Trim First Before Resizing?

J

jtduncan

New member
I've loaded a couple batches of .223 Rem by lubing, resizing and decapping my brass on a Lyman Spar-T turret press with prepared brass.

Once the batch is completed, I've used my Dillon 550B to charge, seat, and Lee factory crimp the rounds. They have cannelures - IMI 55 grain FMJBTs. Just a plinking load. Only a light crimp to ensure a consistent powder burn and slight protection against bullet setback.

I'm also using an RCBS X-die so I'll only need to trim the brass once, then check it's length growth every couple of firings.

Well, got back from the police range with several thousand once fired .223 cases. Already tumbled and cleaned them.

Seems to more efficient to immediately trim my brass to 1.74" OAL per RCBSA directions first. Also using a RCBS Trim Pro Trimmer with a 3-way cutter.

Can I tumble then trim first before resizing?

And then lube the cases up and slap them on the Dillon 550B and resize, decap, prime and then charge and seat in one process? No removing the cases, just pulling the lever.

Seems like I'd be eliminating the use of the turret press and cut out that process.

Has anybody done that? Measured the cases?

Affects on accuracy?
 
K

KP95DAO

New member
X-die: The cat's meow.

If you are using the RCBS X-die you will not get any growth. I have 308 cases that I've resized ten times with no lengthing. I think the X-die is the cat's meow.

You will need to camfer and deburr after sizing, at least I do. But then, I am interested in shooting those sub 3/4" ten shot groups.
 
A

Andy Chadwick

New member
I always resize, trim, then tumble unless the cases are really dirty, then I'll tumble them first and again after trimming. I feel it's important to tumble them last to remove any brass shavings that might be clinging to the case.
 
Y

yankytrash

New member
I don't really get that "X-Die" thing, but if I understand correctly, once-fired should be fine to just slap it in the machine and go, no trimming. I could be wrong, never messed with new fangled stuff.

Maybe give it a try anyway, some with no trimming, some with, some in the order you want to do it in, some in the order it's supposed to be done in, all the while keeping a close eye on the measurements. Work in small batches for experimentation.

Give us a report. I'm curious. Remember, when it's RCBS, you got a good warranty. If you break it, they'll replace it.
 
A

Art Eatman

Staff in Memoriam
It has been my understanding that elongation of a case neck comes from the repeated shock-loading on the shoulder from firing. This acts to extrude the brass very slightly forward with each shot, finally exceeding the specified overall length.

Elongation from resizing should be miniscule at worst, seems like. The push on the case neck by the resizing die is toward the rear of the case, although there is a forward pull exerted by the expander...

Art
 
C

cheygriz

New member
Conventional wisdon sez to size first. However, I've done it both ways, and both ways work quite well. If I trim B4 sizing, I trim about .002 short, and after sizing, they're right where I want them.

I sometimes wonder if the advice to size first isn't one of those rules that we still have around just because "we've always done it that way."

Try it both ways, and see what works for you.
 
You must log in or register to reply here.
Top