Help with belted magnums

RyBoy

Private
Minuteman
Nov 20, 2019
16
8
6
I am just starting to try to squeeze as much accuracy out of my 7mm rem mag as I possibly can. So far I have been testing loads with new brass (Norma and Nosler) and I have found a couple of recipes that I am getting great groups with. But now it is time to size my once fired brass and I am trying to narrow down the best sizing methods. I have both the Redding competition FL die and the Redding competition neck sizing die for it, but I keep reading about the Larry Willis collet dies. Do they FL size the case? I keep reading that if I want to get maximum accuracy I want to just neck size the brass so that I am headspacing off the shoulder instead of the belt. (Please excuse me for sounding like a nube) So should I use my neck sizing die until I have chambering issues then FL size them? Or should I just order the Collet dies and stick with that?
 

Jrb572

Full Member
Belligerents
Dec 7, 2008
1,489
93
154
Mo
Don’t use the neck sizer. Always full length size. I have the Larry Wills die and have not had a use for it yet. I only have one reload on my brass. I have heard it for after multiple resizings. So far my Redding die seems to size the case all the way to the belt. Hopefully someone else will have experience with the Wills die
 

pabrousseau

Private
Minuteman
Dec 18, 2018
66
12
12
you can take a case and fire it a few times neck sized only to get a fully expanded case for a good head space length or start a spent primer in a case and close the bolt and measure shoulder to primer for the length . then set up your fl sizing die to push the shoulder back .002. the Willis collet die is used to size the portion of the case just above the belt that is not sized when only bumping the shoulder back a couple thousandths which prevents the die reaching the belt. the case is expanded just ahead of the belt making it difficult to chamber or wont chamber at all. the Hornady h.s. gage is the tool you need. if a chamber is cut perfectly there would be no need for the Willis die but the distance from the belt to the shoulder is often quite generous and if you size all the way to the belt the shoulder is pushed too far back causing case head seperation.
 

RmeJu

Sergeant of the Hide
Belligerents
Minuteman
Apr 23, 2019
111
35
34
I have the Redding FL sizer. Works great for me.

Might you squeeze another couple dozen thou out of your groups with better reloading equipment or techniques? Maybe. But getting out and shooting more is going to pay better returns faster than that... and maybe enough that you won't want to bother
 

nn8734

nn8734
Belligerents
Feb 26, 2013
1,556
1,208
219
Las Vegas, NV
I am just starting to try to squeeze as much accuracy out of my 7mm rem mag as I possibly can. So far I have been testing loads with new brass (Norma and Nosler) and I have found a couple of recipes that I am getting great groups with. But now it is time to size my once fired brass and I am trying to narrow down the best sizing methods. I have both the Redding competition FL die and the Redding competition neck sizing die for it, but I keep reading about the Larry Willis collet dies. Do they FL size the case? I keep reading that if I want to get maximum accuracy I want to just neck size the brass so that I am headspacing off the shoulder instead of the belt. (Please excuse me for sounding like a nube) So should I use my neck sizing die until I have chambering issues then FL size them? Or should I just order the Collet dies and stick with that?
I use Redding FL sizing die (and match seating die) for my Mk13. 99% of the time they are sufficient provided the die is set up correctly relative to your target headspace. I shoot for a cartridge - chamber headspace clearance of .002” (.003” max). I headspace based off the shoulder like any other cartridge.

I also have the Willis belt sizing die. I occasionally use it to resize the webbing just above the belt but its primary utility for me is it’s use as a “case body” gauge. After I run a case through the sizing die and measure casehead-shoulder with my Hornady head space comparator tool, I’ll drop the sized case into the top of the Willis die to see if it falls freely into the die body up to the belt. If it does, the case goes on to be primed.

Willis die with collet (being used as a gauge in this pic)
8AF5B324-7B53-4B51-B430-0D1D8E269B49.jpeg
Hornady head space comparator tool with D400 bushing (gray)

D99DD09F-3B2C-4DE7-995F-7A04F8B3D37F.jpeg

I think the Willis die more of a nice to have vs mandatory unless you have a large number of fired cases with excessive diameter (bloating) just above the belt, preventing the brass from being smoothly chambered after full length sizing. Then perhaps it’s worth it to try and save those cases. It’s also not 100% effective as some cases are just too far gone in the webbing.

Example of bloated webbing above belt
D76BDD9C-2ABB-4232-8EEC-D0539A9BBEA8.jpeg
 

RyBoy

Private
Minuteman
Nov 20, 2019
16
8
6
I use Redding FL sizing die (and match seating die) for my Mk13. 99% of the time they are sufficient provided the die is set up correctly relative to your target headspace. I shoot for a cartridge - chamber headspace clearance of .002” (.003” max). I headspace based off the shoulder like any other cartridge.

I also have the Willis belt sizing die. I occasionally use it to resize the webbing just above the belt but its primary utility for me is it’s use as a “case body” gauge. After I run a case through the sizing die and measure casehead-shoulder with my Hornady head space comparator tool, I’ll drop the sized case into the top of the Willis die to see if it falls freely into the die body up to the belt. If it does, the case goes on to be primed.

Willis die with collet (being used as a gauge in this pic)
View attachment 7258794
Hornady head space comparator tool with D400 bushing (gray)

View attachment 7258797

I think the Willis die more of a nice to have vs mandatory unless you have a large number of fired cases with excessive diameter (bloating) just above the belt, preventing the brass from being smoothly chambered after full length sizing. Then perhaps it’s worth it to try and save those cases. It’s also not 100% effective as some cases are just too far gone in the webbing.

Example of bloated webbing above belt
View attachment 7258798
Man I appreciate you taking the time to reply with pictures. That is extremely helpful. I will probably order the willis die just to have it and use the same way that you do.

What kind of brass are you running and how many firings and resizings are you typically getting before the bulge in the webbing?
 

WeiserBucks

Sergeant
Belligerents
Feb 13, 2017
1,068
948
219
Weiser , Idaho
In my experience with Norma and Nosler brass in 7 RM and 300 WM I lose the primer pockets before I need the collet die . I get 4-6 firings on the brass and throw them away. I use Redding FL dies and bump the shoulder .003", accuracy is great but the primer pockets just don't hold up very long at max pressure.
 

nn8734

nn8734
Belligerents
Feb 26, 2013
1,556
1,208
219
Las Vegas, NV
Man I appreciate you taking the time to reply with pictures. That is extremely helpful. I will probably order the willis die just to have it and use the same way that you do.

What kind of brass are you running and how many firings and resizings are you typically getting before the bulge in the webbing?
No problem, man. Glad they helped!

On my current barrel I have 150 rounds down the tube. 100 of those are 1x federal mil brass and 50 are 1x Federal commercial brass. In the case of the military brass (mk248 mod 0/1) I have lost 10 pieces due to loose primer pockets and/or bloated webbing. I use Fed 210m, 77.1g h1000 and 190 smks which produce a high single digit SD over 10 randomly selected rounds (MV is 3050 fps and ES is usually in the low-mid 20s). Commercial brass has produced similar figures with an identical load, except i use 77.4g in the commercial brass. The barrel has another node at 80.1-80.3 but I elected not to use it, trading about 100 fps MV for longer barrel and brass life.

The rifle’s previous barrel, I used Winchester and Remington brass across two different loads (190 and 210 Bergers)...All that stuff was store bought brass and I managed four-five firings on average before I noticed elevated numbers of loose primer pockets. Didn’t have too much of an issue with bloated webbing. My SD/ES using either Win or Rem brass were not as good as what I’m getting with the Fed mil and commercial brass.

My Mod 5 uses the Mk248 mod 1 reamer which allows for higher charge weights safely relative to most other 300 win mag reamers /chambers.
 
  • Like
Reactions: RyBoy

TxWelder35

Online Training Member
Online Training Access
Belligerents
Minuteman
Oct 17, 2018
669
635
99
DFW
In my experience with Norma and Nosler brass in 7 RM and 300 WM I lose the primer pockets before I need the collet die . I get 4-6 firings on the brass and throw them away. I use Redding FL dies and bump the shoulder .003", accuracy is great but the primer pockets just don't hold up very long at max pressure.
You are only getting 4-6 firings on norma brass in 300wm?
 

skipjack

Private
Belligerents
Feb 28, 2013
145
73
34
I personally only neck size until the brass tells me it’s time to full length. I’ve been doing that for years. Your taking the belt out of the equation that way. I personally don’t see why it is standard operating procedure for beltless and not belted.
 
  • Like
Reactions: Muley Buck

Dobbs02si

Private
Minuteman
Jan 24, 2020
48
32
24
If you're going to FL size I stand by the redding comp shellholders and space off of the shoulder, not the belt. I only used big box federal brass to load 180gr bergers over 68gr of h1k, and primer pockets were gone in 3-4 loadings. That was enough of the belted brass for me.

I also agree with the others to neck size. I FL only when I feel any resistance chambering.
 

Culpeper

"Goodbye, Rutten"
Belligerents
Nov 25, 2006
4,276
2,851
219
61
Roswell NM
Willis is snake oil. Don't you people know the only magnum that needed the belt was the Holland & Holland. Do you even know why? It does work on the H&H though. The top of the die is the gauge. If you drop a WM in and the web is bloated its not the brass.
 

nn8734

nn8734
Belligerents
Feb 26, 2013
1,556
1,208
219
Las Vegas, NV
Don't you people...
1582766432240.gif

Lol, yea agree about the snake oil bit...though not sure what you mean by “if you drop a WM in and the web is bloated it’s not the brass”.

Are you trying to say that if the web is bloated in a win mag case, the gauge isn’t going to give a reliable indicator as to whether it’s still usable or not?

Or are you saying that the pressure in that load was simply too much and any brass would experience excessive expansion under an over charge condition (i.e. its the person doing the reloading, not the brass)?

If neither, can you explain?
 
  • Like
  • Haha
Reactions: Fig and Culpeper

rollerdog

Private
Minuteman
Dec 18, 2019
3
0
2
I started using a Redding F/L die on a 338 RUM. The shoulders were getting set back .005+ inches before the stripped bolt would close with no tension. Almost ordered the Willis. Bought an RCBS set on a whim... Problem solved...
 

Culpeper

"Goodbye, Rutten"
Belligerents
Nov 25, 2006
4,276
2,851
219
61
Roswell NM
If it is not headspace off the belt there shouldn't be room for the case to bloat enough to not fit in the gauge. Willis will at least tell you that much. Lot of shitty chambers to help Willis unload his investment a few dies at a time here and there on the net and he is always crawling for new threads to do just that. If he is not in the hospital with diverticulitis he might show up. He still uses a flip phone so it will be off his XP and CRT.
 
  • Like
Reactions: nn8734

RyBoy

Private
Minuteman
Nov 20, 2019
16
8
6
No problem, man. Glad they helped!

On my current barrel I have 150 rounds down the tube. 100 of those are 1x federal mil brass and 50 are 1x Federal commercial brass. In the case of the military brass (mk248 mod 0/1) I have lost 10 pieces due to loose primer pockets and/or bloated webbing. I use Fed 210m, 77.1g h1000 and 190 smks which produce a high single digit SD over 10 randomly selected rounds (MV is 3050 fps and ES is usually in the low-mid 20s). Commercial brass has produced similar figures with an identical load, except i use 77.4g in the commercial brass. The barrel has another node at 80.1-80.3 but I elected not to use it, trading about 100 fps MV for longer barrel and brass life.

The rifle’s previous barrel, I used Winchester and Remington brass across two different loads (190 and 210 Bergers)...All that stuff was store bought brass and I managed four-five firings on average before I noticed elevated numbers of loose primer pockets. Didn’t have too much of an issue with bloated webbing. My SD/ES using either Win or Rem brass were not as good as what I’m getting with the Fed mil and commercial brass.

My Mod 5 uses the Mk248 mod 1 reamer which allows for higher charge weights safely relative to most other 300 win mag reamers /chambers.
Thanks again man. I've had pretty good luck with nosler brass. I got my SD down to single digits in my 25-06 with h4831sc and WLRs. I started sizing down lapua 30-06 and got my SD/ES down a little bit more and I saw more reloads out of the brass. I'm using both brands of brass now, but nosler hasn't been bad for me.

I'll post my results with my 7RM. It's just a factory Remington Sendero. You like H1000? It seems to be more consistent than retumbo. I'm using H4831sc in the 7RM right now, but I was going to try out H1000 and maybe RL 25.
 

nn8734

nn8734
Belligerents
Feb 26, 2013
1,556
1,208
219
Las Vegas, NV
H1000 is the shit. I don’t use anything else for my magnums. It burns very clean compared to most other powders and very consistent lot to lot from what I have seen.
 
  • Like
Reactions: RyBoy

Culpeper

"Goodbye, Rutten"
Belligerents
Nov 25, 2006
4,276
2,851
219
61
Roswell NM
Good morning. I should add the Willis holds the patent to his die and he has had offers from some majors and he turns them all down. Something to be said about that. And that it is not too expensive and it won't hurt to grab one up while they are around if you find that you need it. He designed and had it manufactured himself on his own dime. It's his inventory and that is all there is on the shelf The only reason I have a precision R700 in H&H is because of that die. The subsequent magnums use the same parent case and are an improvement over the 300 H&H. But nothing extracts as smoothly as a 300 H&H and is a go between with the 30-06 and modern magnums. But people should know the belt on modern mags are there just for the term, "belted mag" and nothing more. It is just a throwback to 1925.
 
  • Like
Reactions: RyBoy

RyBoy

Private
Minuteman
Nov 20, 2019
16
8
6
Good morning. I should add the Willis holds the patent to his die and he has had offers from some majors and he turns them all down. Something to be said about that. And that it is not too expensive and it won't hurt to grab one up while they are around if you find that you need it. He designed and had it manufactured himself on his own dime. It's his inventory and that is all there is on the shelf The only reason I have a precision R700 in H&H is because of that die. The subsequent magnums use the same parent case and are an improvement over the 300 H&H. But nothing extracts as smoothly as a 300 H&H and is a go between with the 30-06 and modern magnums. But people should know the belt on modern mags are there just for the term, "belted mag" and nothing more. It is just a throwback to 1925.
Thanks dude. Yeah I'm putting an order in for one of Willis' dies. I kinda feel like it's one of those things that I'm lucky to get and in twenty years there won't be anything that good out there. I've never even considered an H&H but I'll definitely look into it when it's time to re-barrel.
 

WeiserBucks

Sergeant
Belligerents
Feb 13, 2017
1,068
948
219
Weiser , Idaho
Thanks dude. Yeah I'm putting an order in for one of Willis' dies. I kinda feel like it's one of those things that I'm lucky to get and in twenty years there won't be anything that good out there. I've never even considered an H&H but I'll definitely look into it when it's time to re-barrel.
You can't be serious?
 
  • Haha
Reactions: RyBoy

Culpeper

"Goodbye, Rutten"
Belligerents
Nov 25, 2006
4,276
2,851
219
61
Roswell NM
300 H&H is for nostalgia reloading and is safe up to 54,000 PSI. It's is only being described here because it is relevant to the belt and the die and just about every later 300 Mag. Parent case lineage. I can reload to duplicate between 30-06 and 300 WM. After reloading it for 15 years I will probably retire it. The RUM can be reloaded down or up to different power levels with a much better case based on the 404 Jeffery rather the 375 H&H. I only had it built for midrange F-class with no brakes to compete against other 300 mags and at the end of the day I wasn't fucked up like the rest and extraction was never a problem. Probably the easiest extracting mag design with those steep shoulders but excessive unchecked bulging will destroy a stock R700 extractor, which sort of defeats that purpose. It was a smart move. It also a smart move for magnum hunting. Still in wide use. Especially, overseas on rifles most of us can't afford up against dangerous game where easy extraction is sort of important. Those people shoot once fired high end custom loads and don't live in our world.

If anybody wants an H&H case just to look at and have send me a PM. 300 magnum precision shooting started there with cordite and corrosive primers that destroyed the case for reloading. If Ben Comfort were still here today he would outshoot all of us with that load.
 
Last edited:
  • Like
Reactions: RyBoy

supercorndogs

Ham Fisted Gorilla
Belligerents
Feb 17, 2014
4,602
3,103
219
Colorado
I haven't been shooting my new 300wm barrel much. I left minimal headspace at the belt hoping to not experience the secondary belt forming. With the factory Remington barrel, I needed to size the area in front of the belt, after about the 8th firing. The belt is useless on the modern mags, but the chamber is still cut to headspace off the belt. If you want to headspace off the shoulder, you need reload for them. I have the LW collet die because I needed it. It worked to size the area in front of the belt that was giving me hard chambering and sticky extraction.

The thing with snake oil is, that it doesn't work. Calling something that works "snake oil," is not the proper metaphor.
 

Culpeper

"Goodbye, Rutten"
Belligerents
Nov 25, 2006
4,276
2,851
219
61
Roswell NM
You're expecting more out your brass than it wants or was designed for. Every once in a while I see people snake oil themselves into a separated case. So, it's your prerogative to keep squeezing the web back into place. Knock yourself out. And don't forget the fucking brake.
 

dukelog

Private
Belligerents
Aug 10, 2010
18
1
6
45
On new 7mm Rem brass, there may well be a pretty sloppy fit in the chamber. Yes, in theory, the case would headspace on the belt. But brass is mass produced, and so are most chambers unless you had your cut professionally.

Consider necking new brass to 30 cal, then sizing the neck back down in your 7mm dies until you can close the bolt with a bit of resistance. What you'll see is a "ghost shoulder" where the 30 cal neck still exists between the 7mm neck and the shoulder junction. At any rate, this little ring at the base of the neck will ensure your case fits snugly between the bolt and front of the chamber. It centers your brass, and ensures a fireform that places your shoulder where it needs to be for your chamber without stretching your brass above the belt on that first firing. I have found this makes my 7mm Rem brass last longer.

BTW, I do this same process with other belted mags for the same reason. Another great candidate is the old 303 Brit. Those SMLE chambers are deep, and usually out of round. I neck the 303 brass up to 8mm (.323) and then run them back through the 303 dies to make a ghost shoulder. The 303 Brit has a bad reputaion for case head separations, which is usually attributed to the rear locking bolt, but that's hog wash. The savage 99, all the winchester and marlin lever actions, and the older Rem 722 lock in the rear, but no one complains about brass life in those. The culprit in the 303 Brit is that first firing in a super sloppy chamber.
 
  • Like
Reactions: RyBoy

GBMaryland

Sergeant
Belligerents
Feb 24, 2008
873
752
99
Maryland, US
I don’t know if anyone mentioned this, but using a collet resizer is always a good option.

Problem with belted mags is metal migration from the rear of the case to the throat/neck.

Especially, narrowly necked cartridges like a 375 H&H.

If you are using the cartridge in the SAME rifle, you can neck resize. However, you always need to trim the cases after the first reload. (Most factory cases are shorter than spec...)
 
  • Like
Reactions: RyBoy

supercorndogs

Ham Fisted Gorilla
Belligerents
Feb 17, 2014
4,602
3,103
219
Colorado
You're expecting more out your brass than it wants or was designed for. Every once in a while I see people snake oil themselves into a separated case. So, it's your prerogative to keep squeezing the web back into place. Knock yourself out. And don't forget the fucking brake.
How are you pinpointing squeezing the web being the point of failure vs thinning at the web from shoulder bump? Why is sizing above the web different from small base sizing?

Running high pressure loads has trade offs. I think that is pretty much common knowledge. Anyone who wants to run overpressure and thinks they are going to get 20 reloads out of their brass is delusional.

My last 300wm barrel had brass make it 16. They had the web squeezed twice. I fired them one more time in the new barrel {17}, and then started load development with some new brass, and different powder. Now I switched bolts and barrels and started shooting 280 Remington out of my long action instead.