Larry Willis collet die

[Mike Matteson]

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.

Interesting. I have and shoot a 308 NM rifle (26"). I shooting 3330fps with 75.6grs with H4350 and Fed-210 primers in Winchester brass. I also shot a 338WM using Fed-210 primers, Rem brass 200gr Nos BT AB @ 3230fps using 75.5grs of W760. (24") The load was develop in very warm weather. Not sure how it does in very cold weather for velocity. Both are under 1/2" groups @ 100yds and hold very good at longer yardages.
The 308NM is necked size with a 300WM neck sizing die. It only size about 2/3 of the neck. That do to die shape. I get 10 to 12 firing from the cases. Primer pocket are loose at that time. That how I stumble onto not bumping the shoulder back on the belted mag cases.
With the 308NM I got a little better grouping with the neck sizing. The left the case partly fire formed into the neck area. That was due to configuration of the WM 300 and the 308NM cases and dies. At the time it would have taken over a year to get a 308NM neck sizing die. All case the neck were cut for thickness at that time also.
At that time I only annealed once. That stopped the neck splitting. Not bumping the shoulder back stop the splitting at the belt. Before that I would lose cases with base separation in 3 firing.

 

[dstancu]

It is a "solution" that doesn't really have a problem. As you can see, it isn't exactly common knowledge that one is needed. I have sized hundreds of rounds of belted brass for 338 and 7mag and never had a need to size differently than any other piece of brass. One reply above alludes to brass that had been shot in a larger chamber initially and his sizing die would not allow him to fit a new, tight chamber. If he had new brass this would not have been an issue. Others that have mentioned this die seem to think it is needed, but offer no real evidence. My Colt Light Rifle has a tight chamber and I had trouble getting used brass to fit. I filed down my shellholder a bit to allow the brass to enter the die a bit more and problem solved. A different sizing die may have worked fine, and new brass would not have been an issue.

I would respectfully disagree. There is a problem, albeit for just a subset, or a fraction of people handloading.
The reason many users of belted cartridges never noticed that they needed to resize the web area of the wall (right above the belt) is simply because their rifles were chambered a bit loose, or closer to the max tolerances of SAAMI for that chambering. That way, the web (where the case is the thickest and the strongest), never expanded enough (bulged) to become difficult (or even impossible) to chamber.
Important note: standard FL (full length) resizing dies do resize the full cartridge, but to a much lesser degree in the lower part of the wall. Small base FL resizing dies do a slightly better job at constricting back to specs the area in question. But especially when using neck sizing dies, nothing touches the lower part, and it keeps bulging until unusable.
Especially in the case of rebarelling with higher quality barrels, the chamber is cut tighter, closer to the minimum SAAMI specs.
The web area bulging problem is a lot less common on beltless cartridges, where the FL resiging does an adequate job at controlling the dimensions.
The Larry Willis die was designed especially to constrict mostly the lower part of the case wall above the belt before it has become too large in outside diameter. The beauty of the die is that one can use the other end as a gauge to determine which cases need the resizing with the specialized LW die.
Different cases (manufacturers) have different metallurgy, some are more prone to expand than others: my Hornady 300WM require the LW die quite often, while my Peterson 300WM do not.

 

[VinceMule]

Mike, just goes to show you that trial and error trumps all! I have always wanted a 308 NM. This is a humbling sport.

 

[Mike Matteson]

Mike, just goes to show you that trial and error trumps all! I have always wanted a 308 NM. This is a humbling sport.

They are slower than the 300WM by100fps. At the time I was developing the load for the 308NM my very good friend had a 300WM. It bested me by 100fps in Ruger #1. We had it dialed in too. He has passed a long time back. I do miss him, because was a friend and we would reload and shoot together. Even worst I didn't get all his reloading info before he passed.
At the range I wouls shoot his rifles. I could always get a better grouping out of his rifle than he could. So I was his load tester. No muzzel brakes at that time.

 

[VinceMule]

Mike, I had a hunting/shooting partner like that also, skin cancer got him.

 

[Bob2650]

The 458 win mag is too narrow at the shoulder but a 416 mag looks big enough to reach the bulge without messing with the rest of the brass.

 

[pgothro]

I would respectfully disagree. There is a problem, albeit for just a subset, or a fraction of people handloading.
The reason many users of belted cartridges never noticed that they needed to resize the web area of the wall (right above the belt) is simply because their rifles were chambered a bit loose, or closer to the max tolerances of SAAMI for that chambering. That way, the web (where the case is the thickest and the strongest), never expanded enough (bulged) to become difficult (or even impossible) to chamber.
Important note: standard FL (full length) resizing dies do resize the full cartridge, but to a much lesser degree in the lower part of the wall. Small base FL resizing dies do a slightly better job at constricting back to specs the area in question. But especially when using neck sizing dies, nothing touches the lower part, and it keeps bulging until unusable.
Especially in the case of rebarelling with higher quality barrels, the chamber is cut tighter, closer to the minimum SAAMI specs.
The web area bulging problem is a lot less common on beltless cartridges, where the FL resiging does an adequate job at controlling the dimensions.
The Larry Willis die was designed especially to constrict mostly the lower part of the case wall above the belt before it has become too large in outside diameter. The beauty of the die is that one can use the other end as a gauge to determine which cases need the resizing with the specialized LW die.
Different cases (manufacturers) have different metallurgy, some are more prone to expand than others: my Hornady 300WM require the LW die quite often, while my Peterson 300WM do not.

Great explanation

 

[ntsqd]

Interesting. I have and shoot a 308 NM rifle (26"). I shooting 3330fps with 75.6grs with H4350 and Fed-210 primers in Winchester brass. I also shot a 338WM using Fed-210 primers, Rem brass 200gr Nos BT AB @ 3230fps using 75.5grs of W760. (24") The load was develop in very warm weather. Not sure how it does in very cold weather for velocity. Both are under 1/2" groups @ 100yds and hold very good at longer yardages.
The 308NM is necked size with a 300WM neck sizing die. It only size about 2/3 of the neck. That do to die shape. I get 10 to 12 firing from the cases. Primer pocket are loose at that time. That how I stumble onto not bumping the shoulder back on the belted mag cases.
With the 308NM I got a little better grouping with the neck sizing. The left the case partly fire formed into the neck area. That was due to configuration of the WM 300 and the 308NM cases and dies. At the time it would have taken over a year to get a 308NM neck sizing die. All case the neck were cut for thickness at that time also.
At that time I only annealed once. That stopped the neck splitting. Not bumping the shoulder back stop the splitting at the belt. Before that I would lose cases with base separation in 3 firing.

My first chamber to reload ever was the .308 Norma. I had case head separations in 2 to 3 firings that I couldn't fix and nothing more vet reloaders suggested worked. When I got a case head separation on one of the factory rounds I knew that it wasn't me. Turned out that the rifle was the problem, 03A3's just aren't made for that. The action was stretching. I had a -06 barrel put on it for show and pretty much retired it.
Recently I ran across a used M70 FWT .308 NM in a shop in Minden, NV and that got me going again. It wasn't what I wanted in a .308 NM, but I've always had a soft spot for the chamber so now I'm slowing building another .308 NM rifle.

Which is to say that I've been following all of this closely. I, too, ordered one of the Willis dies. I may not need it, but if I do it's going to take a while to get. I'd rather that happen while I'm building than when I want to shoot it and can't. These ring dies and the comment above about using a 300 Win die have the gears spinning.....

 

[pgothro]

My first chamber to reload ever was the .308 Norma. I had case head separations in 2 to 3 firings that I couldn't fix and nothing more vet reloaders suggested worked. When I got a case head separation on one of the factory rounds I knew that it wasn't me. Turned out that the rifle was the problem, 03A3's just aren't made for that. The action was stretching. I had a -06 barrel put on it for show and pretty much retired it.
Recently I ran across a used M70 FWT .308 NM in a shop in Minden, NV and that got me going again. It wasn't what I wanted in a .308 NM, but I've always had a soft spot for the chamber so now I'm slowing building another .308 NM rifle.

Which is to say that I've been following all of this closely. I, too, ordered one of the Willis dies. I may not need it, but if I do it's going to take a while to get. I'd rather that happen while I'm building than when I want to shoot it and can't. These ring dies and the comment above about using a 300 Win die have the gears spinning.....

The Wills die brings the case above the Belt back into spec it does not work to stop case head separation in my experience

 

[deputyrpa]

I'm in the need of a Larry Willis collet die
I go to the website and it say backorder!

What is everybody opinion on this die for belted mag

I have one if you want it. I got rid of my belted mags.

 

[ImperfectLiberty]

I have one if you want it. I got rid of my belted mags.

I'm still looking as well, what do you want for it?

 

[deputyrpa]

I'm still looking as well, what do you want for it?

Nothing.

 

[ImperfectLiberty]

I'll take it if that's the case! Thank you so much!

 

[ImperfectLiberty]

It won't let me message you so I can shoot you my info here or you can message me or we can text. Whatever works best for you. I really appreciate it. You have no idea how much that means to me.