sizing and trimming

[lives4huntin]

It would seem to me that a guy should size his case and then trim it. Is this correct? Information is for a .264 win mag. Any other tips?

 

[FieroCDSP]

That's usually the easiest way. If you have loose chamber tolerances like I do (Mosin Nagant) then your primer could back out some on firing and cause your measurement to be off. Plus with Lee trimmers especially you need the primer out anyway, so you might as well size first.

 

[rcmodel]

You have to size first with most any brand of trimmer.

#1 The caliber specific pilot is sized to fit a sized case neck and keep the case centered on the cutter.

#2 The empty case doesn't grow when you shoot it, so much as it grows when you size it back down and all the extra brass has to go somewhere.
That "somewhere" is excess neck length.

If you trim before sizing, you will need to trim again after sizing anyway!


rcmodel

 

[birdbustr]

Size then trim is what I do too. My Forster trimmer doesn't care if the case is primed or not.
I had a Weatherby in 7mm STW that was super restrictive about chamber tolerances. It was so bad I got a Remington Sendero to see if it would be any better. After comparing the rifles side-by-side, I kick myself for ever $$buying$$ into the Weatherby hype. Remington rifles for me from now on.

 

[Walkalong]

Size first. Trim second.

For new Revolver brass I like to shoot it once, then size it, then trim it.

I just Taper Crimp the first time.