Resizing 7mm rem mag.

[JPF]

Gents,

Had an issue when resizing my 7mm last night. Set up the die as always, sized a couple brass and slid them in my chamber, all is good. So I proceed and resize 100 brass, when I'm done I grab a few and find that lots chamber really hard, and some just plain old get stuck. Playing with the calipers, comparing brass that fits and don't fit, I found right above the belt on the brass to be larger on the ones getting stuck. Armed with this info I started reading on the net that this is an issue with belted mags and conventional dies. I read about a belted magnum collet die, is purchasing this die the only thing I can do? Any other options? Thanks for the input

 

[Dogleg]

It's more an issue with horribily oversized factory chambers than with the Magnum case itself. The belt allows the factory to cut chambers worse than normal and it will still work. The tool you mentioned will work, if just cranking your die in a bit more doesn't.

A bush league solution that I use for curing many chambering problems, mostly traceable to useing brass from different rifles is a .300 Win Mag small base die. It will put a bit of extra squeeze on a .300 case, then if you take the expander rod out it becomes a small base body die for .257 Weatherby, .264 Win and 7mm Rem.

 

[noneck180]

Some guys have taken some material off the top of the shellholder..to get the brass to go a little further in the die..not sure if this works with belted magnums..never had any problems.

 

[mmattockx]

Were you full length sizing them, or neck sizing them? My .338 Win Mag brass tends to move the shoulder forward a bit and after 3-4 firings I need to full length size them to bump the shoulder back. After that, they chamber easily again.

Mark

 

[JPF]

I was full length sizing.

 

[JasonS]

I used LEE dies for years loading an A-Bolt in 7mmMag. Never had a problem. Make sure to set the sizing die so it touches the case holder in the ram when the ram is all the way up. Sometimes you even have to turn it a half turn past.

 

[Clark]

If a belted case is fired in one rifle, it may never fit again in another rifle.

Larry Willis and his innovative technology company in his garage sell a die that will fix that.
Or you can segregate brass.

 

[jacky]

I reload 7mm mag and this has never happened to me. Now I believe I am neck sizing as I have about a penny's width between the top of the piston and the die on the upstroke. I have reloaded my brass 4 times without a problem although I have been told to watch what mmattockx is talking about bumping the shoulder back.

My initial thought is that the die isn't set up correctly but I could be wrong.

 

[Dean2]

You can easily get that problem using brass fired in another gun. The small base die idea mgiht fix it, and the advice to talke a couple thou offf the shell holder will help. If neither gives you enough squeeze just above the belt then Larry Willis's die is your only other choice. Personally, at the cost of $45 per 100 I would just go buy a new bag of brass and use them only in the one gun.

 

[ffwd]

This happened to me after I put a new barrel on my 7mm Weatherby. Some of my old brass would chamber, some wouldn't. I was able to turn the die in a bit more, and problem solved. No Larry Willis tool yet.