Most of you may be familiar with Larry Willis's tool for sizing the base of belted magnums. This is his website:http://www.larrywillis.com/
Butch

If the base of a belted magnum (or any other type of case) needs sizing, then the case has been subjected to significantly excessive pressures and should be discarded (as should the loading data which caused this condition).

quote:

Originally posted by Stonecreek:
If the base of a belted magnum (or any other type of case) needs sizing, then the case has been subjected to significantly excessive pressures and should be discarded (as should the loading data which caused this condition).

Some belted magnum chambers are just reamed too large. It almost seems to be standard practice.

It is not just the chambers than run large. The tolerances of factory brass and ammo is terrible. I did a 458 Win. for a customer last August. The chamber was cut and the barrel fitted so there was just a light crush on the "Go" gauge. When he fired the rifle, there was some indication of excess headspace (primers backed out slightly). When we got back to the shop the headspace was checked again. Slight crush on "Go" gauge.I pulled the barrel. I got into the ammo cabinet and got a box of 300 Win Mag ammo. Using one of these rounds, as a headspace gauge, I measured with a depth mic. I showed "dead on". I then got a Rem. 375 H&H round. It dropped into the chamber and the whole belt went in, past the recess of the chamber. I went through every brand of every belted Mag. ammo that I had. I could not believe the variances in the measurements. Oversize chambers are out there but so is undersize ammo.

I bought that tool since it seemed like a good idea at the time and thus far have never needed to use it. I think it's a solution to a problem that must hardly ever exist.

7mm Rem Mag (Savage 110 Tactical) & a 375H&H (Wichester Model 70) are the two belted magnum cases I use.

While I'm sure there are plenty of varying chambers & ammunition pitfalls awaiting the unsuspecting shooter & reloader I've never had an issue with either rifle, their chambers, ammunition, adjusting the F/L dies, etc. so far; and that's many firings for each cartridge with the same batches of brass.

Larry's tool works on my 375H&H cases

I've had one of these dies for a few years now and use it on all my belted mags. Works great and gives you several more firings on your belted mag cases. I believe that it is just above the belt where the belted mags go out of spec. I use the primer pockets to tell me when the case is done. Loose pocket means done case.

When reloading belted cases use the shoulders for head spacing rather than the belt where possible. Dedicate cases for a given rifle. roger

It is not a case of head spacing on the belt or the shoulder although the shoulder is best. It is the fact that the case when it is pushed into the sizing die will not size right up to the belt generally leaving a small raised section of un-resized case that makes chambering dificult. There is as much idifference in the head to front of belt measurement in the different brands of cases as there is in the chambering reamers for these rounds. That is why I have discarded the rifles I had with belted cases. I now stick to just the two and for very good reason.

Von Gruff

I do have to add that if I had come across the collet resizing die beforehand then it might have been a diferent story. They are a good solution to a very real cause of discarding brass well before it is realy due.

von Gruff.

I have a buddy with a couple of custom wbys that have the buldge problem. We got one of the dies years ago and reclaimed the price the first night!! (wby brass worth $1 a piece doesn't take long)

I had a 264winmag built a few years ago with a shilen barrel and had quite a few once and twice fire brass for, but traded the rifle off and bought a 264 barrel for my Encore rifle and none of the brass will fit the chamber, even when run through a FL die. BTW, the loads shot in the custom Mauser were not excessive pressure. I bought all new brass but thought about a die of this style, though I haven't heard of this brand. Is this die similar to the small base dies that are offered?

This is the only die I know of that will size ALL THE WAY DOWN TO THE BELT. Die manufacturers are afraid if they built that into their dies someone would bang into the belt and move it some and you'd have a headspace problem.
That's why this die works....it isn't actually the bulge left by the gun but what happens is the case gets bigger in the chamber and the fl die goes down the side of the brass and when it stops it leaves a bulge just above the belt.

quote:

Originally posted by Stonecreek:
If the base of a belted magnum (or any other type of case) needs sizing, then the case has been subjected to significantly excessive pressures and should be discarded (as should the loading data which caused this condition).

If the case is fired once or twice this would be true, but gradual expansion after multiple firings the brass gradually expands and the dies are generally not designed to resize that part of the brass.

My personal solution was to take a SB sizing die
for a belted magnum cartridge (I honestly don't rememer which one and simply cut it off so that it has no shoulder.

In essence it's a small base body die.

It does the job for me.

AD

allan is right.we made up a small base die to solve the problem.

A few years ago, there was a guy that made a die for sizing right down to the belt.

He posted here on AR reloading to try to boost sales.
He was flamed out of here.
Not by me.
I did not have any belted mags then.
Now I am shooting (3) 300WM, a 7mmMag, and a 338WM.

I have a 300WM and 338WM reamer.

I have tried cutting the belt relief deeper, but still within the sloppy SAAMI tolerances, in a effort to get the headspacing on the shoulder on the first firing and get more accuracy. It did not make it any more or less accurate.

My Ruger #1 7mmMag is very accurate, but heavy. It has a threshold of hot loads that the case will not fit back in the chamber without full length sizing. That threshold somewhere between 55kpsi and 65kpsi in Quickload.

But this thread has me thinking, if I make the belt relief .005" deeper, that could affect resizing the case in front of the belt.