"Bumping" case shoulders??

[ranger116]

What is the best way to bump the shoulders back with .204 brass (never tried it), and can it done using a Colet die? After the third firing the cases are just too tight, but can still be chambered. I'm using both Nosler & Rem. brass, and normally only neck size. Also just had a Pac-Nor super match barrel/action tuned, but had the same issues with the factory tube.

Any help would be appreciated!

 

[Cort]

Collet dies are designed to resize the neck area only. To set the shoulder back, you need to use a full length sizer die. They come in multiple forms: a full length body only sizer, a full length body sizer with a fixed neck sizer and a full length body sizer with a bushing neck sizer. A good answer is to send once fired cases from your rifle to Forrester and have them hone a full length die to match your chamber. Boyd Allen has a recent thread here where he describes neck sizing followed by body sizing to achieve the smallest amount of runout from your case. That approach looks very interesting also.

Cort

 

[ranger116]

Cort -

THANKS, sounds like going the Forrester's route is the way to go. I do have a standard set or .204 RCBC dies (full length.) With a full length die what is the proses to bump them back? Just screw the die in a extra turn or two to bump? I did buy one of those Hornady Lock n load Headspace Gauge kits a while back, but it doesn't describe the the proses to bump them back to a recommended .001/.0002.

 

[Cort]

Since you have the head space gauge, measure your head space before and after full length resizing. Adjust the amount that your die is turned into the press until you run out of adjustment or get the set back that you want. If you have a tight chamber, your dies may not be able to give you the set back you want.

Cort