Got the rifle rebored a few weeks ago. Just got the dies today. Resized 55 338 win mag cases through the 375-338 Redding dies. Cases look good, no issues expanding necks. But, when I tried to seat bullets, they are VERY tight. The first one was tight, and did not seat. I chamfered the neck and tried again and it worked but still tight, the next one after chamfering crushed the shoulder. That was with nickel brass, then I tried regular brass with a chamfer and that was better but still shaving a tiny bit of jacket and seating pressure is high.
This is used brass, most of the primer pockets looked like once fired, but some is probably twice fired.
Should I see if Redding makes a slightly bigger expander button? or Perhaps get an 'M' die. I do intend to load cast bullets in this round, starting bullet size will be .379. Groove size is supposed to be .376, so I might need to drop down to a .378 or even .377. But, if I can't seat a .375 to .376 jacketed bullet, an oversize cast bullet is going to be worse.
I am only using the nickel brass because I have it, I prefer non-plated.
Suggestions?
This is used brass, most of the primer pockets looked like once fired, but some is probably twice fired.
Should I see if Redding makes a slightly bigger expander button? or Perhaps get an 'M' die. I do intend to load cast bullets in this round, starting bullet size will be .379. Groove size is supposed to be .376, so I might need to drop down to a .378 or even .377. But, if I can't seat a .375 to .376 jacketed bullet, an oversize cast bullet is going to be worse.
I am only using the nickel brass because I have it, I prefer non-plated.
Suggestions?