WSM Small Base FL Sizeing Die

[StraightPipes]

Hope everyone had a good holiday.

Back to work;

Im posting this here for a quicker response instead of the reloading board, hope its ok?

Im working on a 7mmWSM chamber and using Winchester brass.
This chamber measures .553 on the back end. Win brass measures .548 out of the bag.
My benchrest FL die that I use currently sizes .552 at the web on fired brass.

The only "small base" sizer on the shelf is from RCBS. I cant get through to RCBS Tech to verify what their die will size to so is anyone currently using this rcbs die?

If you are using one, can you tell me what the case measures after sizing.? Measure from the head-stamp .250 up the case wall. What is the O.D. in this area?

Will the small base sizer do any better than .552 ? If so, how much ?

Regards

 

[BoydAllen]

If your sizing die is making your brass .001 smaller than the chamber, why do you need more sizing?

 

[StraightPipes]

The WSM family generally needs clearance to grow or move around. They are "fussy" , they suffer from "extraction" problems and neck clearance problems just to mention a couple.

Those problems are not "problems" now that I have found clearances that address them.

The issue at hand is "over working" the brass. Using Win brass, you start with .548. SAAMI dims. are .555. Factory chambers are in the .560 zone. Production sizing dies will size at best @ .552.

With these current dims., I will still blow out the cases .005.
I have the chamber to do the job, now I need to size them properly.

 

[BoydAllen]

A friend has a 7mmWSM that is his favorite hunting rifle. It is a ground up custom, based on a Remington Titanium action. The only problem that he has had is that the annealing of the Winchester brass is inconsistent. This has resulted in problems chambering some cases that have more spring back. Gaging cases showed extreme differences in shoulder bump at the same die setting. He bought an automated rotary annealer and set it up so that the annealing line is about 3/8 below the point of the shoulder. Now the amount of bump for a given setting has a total variance of about .001, and the problem is solved. You might want to consider this as the probable source of case fit problems for this brand of brass in this caliber.