I have a Whelen that has a tight chamber. I can't chamber brass that has a shoulder diameter greater than .439". I took a chamber cast and the shoulder is .440". I've read that standard cartridges can be up to .441". Can someone please tell me what the minimum Saami spec for the chamber shoulder is? I'm thinking I might need to have the chamber finished a bit.

My SAAMI drawing shows the following:

Maximum cartridge diameter at shoulder = .4410"

Minimum chamber diameter at shoulder = .4425"

If you want a copy of the SAAMI drawing, PM with your email address.

dedseven,
Do you have your numbers backward?
Butch

Are you sure that your case mouths are not bottoming out in the chamber?

James

Thanks for the information. Yes, I'm sure it isn't the case mouth. It is binding on the side of the brass right at the shoulder. I was trying to resize some fired 30-06 brass and my RCBS die would only resize the shoulder diameter down to .441 and the brass wouldn't quite fit in the chamber. Pushing back the shoulder didn't help. The diameter of the brass is too wide towards the shoulder.

Today I bought another RCBS die and this new die resizes the shoulder diameter down to .339 and the cartridges now fit.

I'm debating whether I should have the chamber finished to meet the minimum specs. There isn't much difference between the current .4400 diameter and the .4425 minimum spec, but it might mean that I couldn't fit some factory brass. A friend of mine is going to let me borrow a go-gauge. I'm going to see whether the bolt will close on that.

Butch,

My numbers are right off the SAAMI drawing. As I read it, if both cartridge and chamber are within spec, there will be AT LEAST .0015” clearance at the shoulder. Swap the numbers and you have a .0015” press fit at the shoulder. Kind of a “sticky” situation!

Dedseven,
I read it wrong. One says chamber size and the other says brass size.
Butch