Home Forums Reloading Big Game Rifles 7MM Brass Sizing Problem

I'm guessing I'm missing something simple. It seems that happens more and more everyday. Anyway, here is my situation and my problem. I have some once fired 7MM Magnum brass. I guess it's possible some of it may be twice fired as I've had it for years; but, I think it is once fired. I was going to do some load work-up for another 7MM Magnum but the brass won't size to fit my rifle. O.K. more specifics.

1) Brass is both Winchester and Remington.
2) Factory rounds chamber great.
3) My sizing technique is to usually size the brass to fit the chamber rather than to size back to factory specs. However, I've finally gone so far as to screw the die all the way to the shell holder, lower the ram, and screw the die down even further, about 1/4 turn. The brass still will not chamber.
4) I thought, maybe it's just an empty brass problem with a push feed rifle; so, I seated bullets in three pieces of brass which were sized back to factory specs (not measured) and they still won't chamber.
5) As the brass was fired in various other 7MMs have they formed and brass-flowed such that I can't get them to fit this chamber or am I missing something?

Thanks in advance.

Max

Sometimes a FL die won't size the case enough right in front of the belt.

I've experienced this with a tight chambered .300 WM.

This may be your answer. Sorta expensive, price is up from when I bought mine. But they work.

http://www.larrywillis.com/

DF

Check the belt. If it is expanded at all, just the very front of it toward the case mouth, the case will not chamber. I look for a shinny ring there.. The cases at one time could have been over pressured.
If you section a mag case, you will note a very small portion of the belt covers the combustion chamber, and that is where it expands.

Other suggestion would be to cover a portion of the case from mouth to head with a black sharpie, run the case in as far as it will go, extract, look for rub marks.

Good Luck

I agree with Dirtfarmer that you need the Larry Willis Collet die. I bought one when I was using brass between different rifles because some of the chambers were a little larger than others. This die fixed that problem.

IIRC, they were around $85 a while back. I thought I'd lost mine, couldn't find it.

So, I bought another one. Eventually found the first one in my .300 Win Mag RCBS die box...

I sold the extra one for about what I paid for it. Should have waited; could have made a profit...

I'm sure it's expensive making them, but the latest price is pretty steep. Glad I already have one.

Good thing, one die works for all conventional Mag cases. (not the big mags, like 378 Wby, etc.) But it will work on the .375 Wby.

DF

Have you checked the overall length of the cases? This one is easy to check. If this isn't the problem I would expect a problem with the sizing in the vicinity of the belt.

Jim