Belted Magnums: Reloading Fired Brass from Another Chamber?

[Chuck R.]

Guys,

I'm working on re-forming 7mm RM brass for my .350 RM using once fired brass form another forum member. 95% of the time, there's no issue, but 5% of the time I end up with brass, although FL sized, will not chamber.

I reload for both 300 win Mag and my .350RM and have not had this issue with brass that's only been fired in those chambers. My normal procedure is to back off from FL sizing by .003-.004" to fit my chambers and headspace off the shoulder.

A quick search shows threads on other forums concerning a bulge in front of the belt that seems to be pretty common. This die seems to be the cure:

https://www.larrywillis.com/

Has anybody else had this issue? before I do what I normally do and buy another cool tool, is there another solution?

 

[ParallelCode]

I bought the belted magnum collet die, though I have yet to actually use it. I haven't seen another die that aims to solve the belt bulge, so I'm curious to see the responses in this thread.

 

[murray brook]

Most of the time when you get the bulge in front of the belt it comes from a die that does not match up very well with your chamber. You set your die up to headspace on the shoulder and give you .002-.003 bump. When this happens with a mismatched die it leaves a very small portion of the case unsized just north of the belt. With repeated firings this area expands and gives you hard chambering, to the point of not being able to work anymore. If you adjust your die down, this portion will get sized and give easy chambering but your bump will be way too much resulting in case separation. Your options can be the Willis die (I have one) it is fairly expensive but works. Another less expensive way (depending on the cartridge) would be to us a longer belted mag sizing die. For example if you had this problem with a 300 Win mag what you could do is adjust a 300 Weatherby mag case tight to the shell holder and size this bottom portion of your case without worry of touching the shoulder then run your case through your shoulder adjusted 300 Win die for proper shoulder bump and neck tension. I discovered this method after I purchased the Willis die. The 300 Weatherby die could work on 7mm Rem mag-257, 270 7mm Weatherby-or any shorter belted mag where the shoulder or neck would not be touched. A small base 300 Wea die might even be better when using unknown brass. JMO

 

[redcon1]

That particular die fixed a couple of my mil surp 300 win mag cases that had your problem but not all of them and I would have to say that, ultimately, it was too much work to be worth it and I just tossed the brass. I ended up having to buy factory ammunition which I shot in my chamber and then reloaded that. This was during one of the Obama panics when you couldn't find good brass anywhere.

 

[Chuck R.]

Guys,

Thanks for the info!

Using factory loads or new brass unfortunately isn't an option for the 350RM, at least not for the foreseeable future. That's the reason I started forming it from 7mm RM. New belted mag brass that I can use for a parent is also pretty expensive now.

IF it was only the .350Rm forming and losing a few now and then I could probably live with it although it does take some time to form the brass before I realize it won't work. Looks like I'll start measuring in front of the belt to get an idea of the odds. The other solution is to just use new brass, which while costly is viable and the 350RM isn't exactly a high volume cartridge, especially in a sub 7lb carbine.

The other, about to happen issue, is I'm re-furbishing my Rem 700 in 300Win Mag and going to re-barrel keeping the caliber, with a Bartlein 2B which is sitting in my gun room now. "In theory" I could end up with the same issue with the fired 300WM brass I have on hand (which is quite a bit) when the new chamber is cut.

I've read about using a 300 Weatherby Die to size 300WM, but some of the posters on "Shooters" still had the issue as the 300 Weatherby die didn't size the bulge down far enough. Apparently the Willis die can also be used on loaded rounds (like the ones I have now that won't chamber), so I can easily fix some of my mistakes.

So I'll go ahead and get one on order, my wife will probably want to gift wrap it and put it in my stocking.

 

[Bwana John]

I’ve had this problem with 2 7mmRemMags, and a 375 H&H.

The Willis die solved the problem

 

[Chuck R.]

I’ve had this problem with 2 7mmRemMags, and a 375 H&H.

The Willis die solved the problem

Thanks!

That pretty much tracks with what I've read and some video's. Some guys don't have an issue but if you do, it's the tool to get.