Sizing die Question

[sixshootertexan]

This question is about how small should a die squeeze the case to. This is just a generic question for all calibers. Lets say we are loading a .303 British. The bullets are .312" diameter. The expander is .310". How small should the die make the brass .306"- .308" before the expander opens it back up to .310"?

I have a set of dies that is going all the way down to .298". I think it is over working the brass and in some cases crushing it some to have run out in the brass. Wall thickness varies .001".

Thanks Ricky

[RBHarter]

Yep that's overworking the brass some .303-.305 would be better . If you have access you might try a 300 WSM for neck sizing . I have a 30-30 with full body dimensions and use a 308 sizer to neck size the thinner brass and larger neck dia in the die only sizes down to .306 for loading .309 paper patched and .310 cast . I think a WSM die would do the same for the 303 .

As a more permanent solution the die can be lapped larger . I've read about it but never done it as I have many alternative dies to try where needed.

[sixshootertexan]

I work at a machine shop so I can get it opened up. I went ahead and got an older set of dies and they are sjzing dowm to .308".

[Ohio3Wheels]

In theory the sizing die should return the case to the SAAMI specs and if properly adjusted most do the job. Then there are the out lyers. If that's a new die I think I'd have a speak with the manufacturer.

Make smoke,