Setting dies for sizing

May 6, 2003
After I fire my virgin cases, and the brass is sized to the chamber dimensions, how do I go about setting my RCBS die so I will acheive optimum accuracy and still get good brass life?

P.S., this is for a belted round, if that matters.


Well-Known Member
Jun 12, 2001
Palmer, Alaska
Set the die up so it touches the shellholder and back it off a couple turns.

Lube the case and run it in and see if it chambers, it probably won't.

Turn the die down an 1/8 turn each time and try it again until it finally chambers easily.

Back the die off a 1/16th turn and see if it still chambers easily, if it does, run the case up in it agin and tighten the lockring on it there.

If it doesn't, turn it back down 1/16th turn and run the case up in it and lock it down.

Often refered to as "partial FL sizing", basically keeps the shoulder from bumping back farther than necessary creating excess headspace.

Yours has a belt, so that isn't happening any way but, it still will keep from working the shoulder area as much and offers better alignment by way of keeping the shoulder tight. Seating the bullets into the lands is best for that though.

That's what I do "if" I "need" to FL size. Get a good neck die and this will do more for case life than anything, especially if you keep them annealed every three to four rounds.

What are you shootin, maybe a 7mag?
May 6, 2003
Thanks for the quick response. I just loaded the rounds up with virgin brass, and ran them through the sizer to get the case mouths round. Hopefully I will have some 1 fired cases tommorow to try the method you described. Isn't is possible to set a FL die to only neck size a case? Or is partial sizing the only alternative?

I am shooting a 7 Rem, and this is my first experience with reloading a belted case, for accuracy to boot. Before it was just reliability issues.

Thanks again.


1) Get a shoulder bump guage and set your die up to bump the shoulder .0015"

2) measure your belt height to base and cull any cases that are too high.


Well-Known Member
Apr 18, 2003
Newburgh NY
I usually color the neck with a marker
(preferably black) and start with the die set high. I slowly wind the die down until the line left by the sizing die meets the shoulder neck junction. this causes the neck to be fully sized however does not push the shoulder back at all.

Trending threads

Nightforce has great tracking capabilities, they are rugged, a bunch of elevation, holds zero forever, and reticles are designed for long range shooting. So if you are looking to shoot long distances constantly, then you need a scope that can take the abuse. -- gilmillan1

Culture Of Excellence At Nightforce Optics
By Len Backus

A high level of quality both in production and in service. Read More

Nightforce is such a solid combo of reticle, available elevation, glass that is good enough to shoot at the longest range you can dial. Nightforce has bullet proof construction that can handle the incidental horse rolling or some other rodeo action. -- bigngreen

Nightforce ATACR Scope Review
By Jeff Brozovich

The new NightForce ATACR is for sure a top choice for any long range shooter. Read More

The total package. Nightforce is the best I have used as far as turret feel and solid detents. I have never had one that didn't track right on and always return to zero. Nightforce NXS is the best value for everything I need. -- Broz

Nightforce Velocity 1000 Reticle Review
By Scott Shreve

I think Nightforce knocked it outta the park with this reticle! Read More