Larry Willis collet die

All these posts of milling the shell holder or die are great as long as they don't end up pushing your shoulder back too far. If this happens then your case life goes to hell. By using a die designed for a longer case then you don't have to worry about this. An example would be using a 300 Wea die on a 300 Win mag case. No way will the 300 Win case shoulder be contacted by the die shoulder of the 300 Wea die. You use the 300 Wea die first to size the portion in front of the belt then the 300 Win die to bump your shoulder to proper specs.
 
All these posts of milling the shell holder or die are great as long as they don't end up pushing your shoulder back too far. If this happens then your case life goes to hell. By using a die designed for a longer case then you don't have to worry about this. An example would be using a 300 Wea die on a 300 Win mag case. No way will the 300 Win case shoulder be contacted by the die shoulder of the 300 Wea die. You use the 300 Wea die first to size the portion in front of the belt then the 300 Win die to bump your shoulder to proper specs.
When the shoulder area is completely removed it isn't an issue. And it become generic to fit all common belted cases.
 
When the shoulder area is completely removed it isn't an issue. And it become generic to fit all common belted cases.
This works when , I believer, you cut your die to make sort of a ring die. This is also a great way of getting around the problem.
 
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When the shoulder area is completely removed it isn't an issue. And it become generic to fit all common belted cases.
I follow what you did. That works for me. I don't see where there would ba any problem with any belted mag case in sizing the area where the belt is by removing the upper part of the die. My problem was with griding a portion of the die bottom off would allow the case going forward and bump the shoulder back even more. By removing the upper portion of the die. Cut the head off at the shoulder so to say. Some places would call that beheading.🤣. Would allow you to size the bottom part of the case without bumping the shoulder back.
I think that most belted cases are the same from the shoulder to the base, and base O.D. is the same too. I presently don't have a reloading manual to verify that, but if I remember correctly the bases are the same. I do note that there is a step at or near the base of the die to meet the belt on the case. Which would stop the sizing of the case. I don't know if that would interfear with the sizing that portion of the case above the belt in getting it back to proper size or not.
With that step in the die at the base would stop the case from going forward at that point. That should work, If the die is built correctly in sizing the case near or at the belt.
Probable on eby you can pick up belted sizing die for cheap and cut it down.
I am a firm believer in not bumping the shoulder on a belted mag case or only a few .000" or so, if not at all unless needed. I have and do stop my neck sizing die short of the transition of the neck.
 
My various 7mm mags love very warm loads where they shoot sub 3/8" groups. 100 new cases per new barrel, throw the brass and the barrel away at the same time, start over. After having Lot# of new brass Rockwell tested, brass hardness in some brands will vary 6% over the lot#. So, I know that the soft brass will loose primer pockets, which is to be expected. Soft brass in the Lot# will also develop a ring from case stretch first. I De-Prime with a Hand de-priming tool, throw away brass without much thought when they feel loose. This step saves you from case prep plus priming to find out that the primer pocket is loose where I have a tendency to not toss the case.

I carefully adjust my sizing die down so that the bolt closes easily. Whatever the shoulder set back is what I am forced to live with. I also expect to see the "ring" around the case on the softer brass, which is an indication of case stretch. In the 40 years of shooting the 7 Rem mag, I have only had one actual case head separation, and that was easily removed from the chamber with a 45 caliber pistol cleaning brush. Unless you are blind, the ring around the case is very, very evident prior to a case head separation.

I have found that my Remington, Browning, Savage, and Custom 7 mags shoot their very smallest groups on Full length sized or partially full length sized brass vs Neck Sized brass. On the neck sized brass, I had to lower powder charges(velocity), and I could not run the loads at peak pressures where the accuracy was found to be the very best.

Mismatch dimensions on dies, new brass, and chamber reamers can be a real mess to deal with.
 
Mismatch dimensions on dies, new brass, and chamber reamers can be a real mess to deal with.
This is where the problem lies and being that the belted mags are headspaced off the belt it is much more pronounced with the belted cases than the rimless ones that are headspaced off the shoulder.
 
I have the Willis die. Slow and messy.
Now I am thinking about a .458 Win Mag sizing die.
I doubt that a small base die is needed.
Does anyone even make a small base .458 WM sizing die?
 
This is where the problem lies and being that the belted mags are headspaced off the belt it is much more pronounced with the belted cases than the rimless ones that are headspaced off the shoulder.
The belt was originally designed to control headspace on the 300 H&H, which has a very slight, long shoulder. Modern magnums have a defined shoulder to measure headspace. How many belted magnums really need that belt?
 
I have the Willis die. Slow and messy.
Now I am thinking about a .458 Win Mag sizing die.
I doubt that a small base die is needed.
Does anyone even make a small base .458 WM sizing die?
I checked into it , although not alot, and couldn't find one. I believe that @xtratoy has a good a very good method as he posted on page 7.
 
This is where the problem lies and being that the belted mags are headspaced off the belt it is much more pronounced with the belted cases than the rimless ones that are headspaced off the shoulder.
The Same thing is happening with non belted, well documented.

Xtratoy's method is called a ring die, they work. I am surprised that Redding, RCBS, etc do not sell these.
 
It finally dawned on me that the .458 is a straight walled case. Small base would not be the correct name.
 
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The die's great, and the gauge tells you without chambering a round if you even need to use the die
 

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