Never loaded belted magnum, research turned up this item

belted magnum resize die

Any input appreciated

Resize as if the belt is not there. After shooting virgin brass, neck size only. After the second firing, be ready to bump the shoulder back for a snug fit in the chamber. Just use the shoulder, not the belt to index the brass in this manner.

I like Wilson adjustable gauges to quickly check brass fitment. I use 2x fired brass to set the gauge. Not a must have, but very handy to see what your brass is doing.

You can get them cheaper from various vendors besides Wilson.

https://lewilson.com/adjustable-case-gage

Looks like a useful tool.

To size and get maximum case life, I use a Redding body die and a Lee neck collet die.

Also, on the first firing , neck up the case a bit then size down to create a false shoulder, then fire form.

As the case head spaces on the belt, and is only required to be fired once , it tends to be sloppy , have seen 0.008" slop at the belt, that is why the false shoulder to prevent the initial stretch,

After many cycles you will probably experience increasingly harder bolt closure and a bit of a 'click' when doing that. This requires a trip through a full length size die, then the false shoulder then fire form.

As others generally ignore the belt and head space of shoulder until it becomes an issue.

Totally unnecessary! Don't waste your money on it!

The description on his website is not accurate, i.e. false. A regular full length sizing die (or body die) will size cases all the way to the belt. When setting up your full length sizing die, adjust it to bump the shoulder back about .002" so the cases headspace off the shoulder, not the belt.

Tell that to the FL die I was using for a 257 Wby. I was loading for.

I was able to manage a workaround but that collet die would have been mighty handy.

Good post^^ That's all I've ever done and have never had a single issue. I load for 7mm rem mag, 300wm, 308 Norma magnum, 300 WBY mag, 338wm, and 375H&H. I guess I've just been really lucky. Having loaded thousands of magnums without that collet die. I generally only load my magnum cases about 8 or so times though. Most of what you hear about the belted magnums is hype. There's no difference in reloading them vs standard cartridges. No difference in how they feed into your rifle either. Unless you have a piss poor rifle. All of mine feed belted magnums into the chamber effortlessly. Also, for the OP: If you aren't shooting benchrest competitions, don't neck size like some here suggest. More than likely you are going to use it as a hunting rifle. Just bump the shoulder back .002-.003" and you are golden. You gain nothing by neck sizing, but could lose reliability and function, which is what you absolutely don't need on a hunt. Just buy a regular ol RCBS fl die set and adjust it to bump the shoulder back. Bingo, you are done. What cartridge are you going to be loading for?

I'd only been loading belted magnums for twenty five years before I ran into the situation where the collet die would have been nice to have.

BTW, it was a regular old RCBS die set.

I have one. Don’t use it much, but it works.

Sorta expensive but with brass sometimes hard to find, beats chunking it.

DF

What about a case such as the 300h&h? Not much shoulder there. Seems headspacing off the belt is the best solution here?

Even so I'd say sizing just enough for smooth chambering is the way to go.

I have a 300Win mag target rifle and fully sorted and prepped brass last > of 20 cycles, not inclined to pitch the brass early as a lot of work went into them, something you can't buy.

I had some 7 Mag brass from a Savage that I was going to use in a Tikka. It was sized using a body die and a neck sizing die but it wouldn't fit because the chamber of the Savage was larger above the belt. I used the Willis collet die and was able to return that area to a size that fit in the Tikka. For brass that is fired in one rifle and re-sized for that rifle, I haven't had a need for the collet die.

It can happen with only one rifle involved.

Same deal here. Only needed it a few times but when I did nothing else would work. Well, a custom set of of dies may have worked but the collet works easy enough for those rare cases.

Yep. I did buy one years ago...never had to use it because I set my my FL dies to HS off the shoulder. I am too OVD to use neck sized brass for hunting, ha, never did that either. Its a good idea and IF I still had a 257 WBY I would use it, they bulged too much for my FL die, but I traded sold the rifle to my friend.

The shoulder isn't much but it's there. You still will get separations if you insist on moving the shoulder more than a couple thou.

Thanks for all the input.

I have been shooting the 7 Rem Mag since 1978, never used collet belted mag sizer...never. I bought one when they first came out, never used it, sold it.

Why buy it if you didn't need it?

Yeah, I hear about cases where it is needed. I would buy one ONLY if it is needed. Directed to the OP only.

I have / do load for 4 different belted magnums and have never needed one. I am up to about the 5th or 6th firing of the same Nosler brass (have to look at my records) for one of my .257 Weatherby magnums and have not had a need for that die.

A false shoulder will save life on the initial brass stretch, but I never bothered because I did not know about the technique when I started out. I don't think it mattered a whole lot since I am getting good life out of the brass. It is definitely a worthwhile step to learn though. I found out about it from Big Stick.

Everyone said that there was a problem with the belted mags. I bought one just in case. IDIOT! I shot Rem 700's and Browning A bolts. Later on, I found out that there was a problem with match chambers where the reamer was small or worn, where the chamber was cut small only .002 over web dia. Then the collet die would not go down that small.

European brass, RWS, Norma, and PMC(Korean) can be much larger in the web than American brass. The collet sizer may work on this larger dia brass as reported by one friend that is using a custom barrel and RWS brass.

Larry's die works will all the belted cases, well except .240 and the mega mags, like 378, .460, etc.

DF

best tool on the market

Ya don’t need it till ya need it. Then you really need it.

With brass hard to find and expensive, this die makes a lot of sense.

Otherwise you may have to chunk what you can salvage.

DF

Interesting thread. I guess if you need it you need it. I've been loading for belted magnums for about 25 years now. Started out with the 300WBY and still have that old die set and have used that particular die set for 3 different 300WBY rifles. 2 were sporterized m1917's and my most current one a pre 64 model 70. Nothing with "match" chambers or anything. That may have some influence on what you need as well. I've seen some real tight Rem 700 chambers. Maybe a person would need that special die if you have a tight chamber. Again, I ask what kind of rifle is the OP going to be loading for???

I think I need it. One year old custom 300 WM. New, 0x used reamer. Started with new Peterson "long" brass. That means my headspace is not stretching upon first firing. Actually, .003" crush fit when chambering brass for first firing. After that, set shoulder for .002" headspace. I have a few unfired pieces (.510" in front of belt) in the box, a bunch of 2x fired (.511") and the remainder of my original 100 pc are 4x fired (.513"). All brass/loaded ammo chambers. It's the extraction which is problematic. After round fires, bolt lifts easy enough. It's the case extraction which is difficult. To the point I have to use a short brass rod to tap back on the bolt handle to break the grip of the expanded case on the inside portion of the chamber, right in front of the belt.

I ordered and received the Belted Magnum Collet die. I don't have your typical single stage, ie Rock Chucker, press. I have a Forster Co-Ax and a Dillon 650. First I tried the Co-Ax. Didn't seem as if though I could fully get the press to cam over. Lots of felt pressure as I was trying to size the case. Ended up ripping the rim off a Peterson case. Knocked the case out of the die. Same, .513" in front of the belt. Moved the operation over to the Dillon 650. Was able to fully am over press, hopefully sizing case. Again, ripped off the case rim from a R-P case (Learning not to ruin Peterson cases until I figure this thing out). Case is currently still stuck in the die. Emailed Jay Mueller, Reloading Technologies. He informed me for the Co-Ax press I need a "Shellholder Adapter Plate" made by Forster and a regular shellholder. Both will arrive on Monday. Until then, I will work on other projects.

Alan

First, thanks everyone for your input.

Little background on me and the rifle I will be loading for, then my plan going forward.

I, have been handloading rifle and pistol for 25+ years, dabbled a little years ago in High Power Rifle competition, did not have the time to devote to it. Never the less, I am devoted to getting all the accuracy I can out of my rifles. So not a neophyte when it comes to Handloading. Just never loaded for Belted magnums.

The rifle is Remington 700 CDL 7mm Remington Magnum mid to late 90’s vintage.
I traded into this rifle years ago from a close friend, the rifle has been a safe queen since he purchased, less, than 2 boxes of factory ammo fired. I fired ten or so getting it zeroed and confirming zero way back when. I got what was left of the ammo and a box and half of empty brass fired in this rifle. Did not really want the rifle but it is beautiful and buddy wanted something I did not use anymore, so I figured, I would sell it or trade it.

Did not want to gear up loading for it so, I sold the rifle. New owner fires one round of factory ammo (Federal Fusion) and the bolt locked up, could not extract the fired case. So, I refunded his money and got the rifle back and the fired case.

I, checked the chamber and bore with borescope everything looks fine. I fired 3 rounds of factory Federal Premium 165grn (20 years old), the original owner gave me when we traded. Not a hiccup. Loaded and extracted the fired cases fine. So, what do I do? I have a rifle I really did not want, plan was to use as trade fodder or sell? I am hesitant to sell or trade it, now, it sits in my safe.

Fast forward to last week, find a deal in classifieds, Dillion dies, assorted brass, and few hundred bullets (have not received yet) so I think what the hay, I’ll load for it and use it as hay field rifle. But in the back of my head, I remember there is somethings peculiar about loading for belted magnums, research comes up with the bulge ahead of the belt after repeated FLS, and the above die is the answer.

After some thought and reading all the post above, I’ve measured all the fired brass and ammo, good 70% of the fired brass, measured .514-.516 just above the belt, and would not chamber in the rifle. .5135 seems to be the maximum go with a slight crush.

So, my plan when I get the dies is to FLS some of the brass and PFLS bumping the shoulder a little at a time, measure ahead of the belt, trim to uniform length, and see how they chamber.

If I have to, I’ll purchase the Willis die

Again, thanks to everyone for sharing your experience and knowledge.

You don’t use it that often.

I was looking for my die, couldn’t find it. Assumed I’d loaned it to someone, forgot who. So, needing one, I ordered another. They weren’t as expensive back then. Later found the original in my .300 Win Mag die box.

I sold the extra one. I keep up with it better using the original case.

DF

Measure the BELT..It will expand, and cause hard to no chambering, issues. If you section a belted case, you will notice the belt reaches a few thous, inch above the head of the case. That portion of the belt is prone to expand, and will not be fully resized by the FL sizing die.

I've had the area ahead of the belt needing sizing to chamber.

I've never had a belt to swell. Guess you'd have to be pushing it pretty hard to stretch the belt.

DF

Had one of my 270 wbys rebarrelled. Gunsmith asked if I wanted a tight chamber. I said yes. Wound up with a lot of brass that would not fit. Bought this die and solved my problem. Hasbeen

Any you gained what by having a "tight" chamber?

I've loaded a lot of belted cases and never had a problem. I adjust my sizing die like any other bottle neck case and forget about the belt. But on the rare occasion that you have a problem this die will help.

You may not need it, but if you do, then you do.

Had a .257 Wby. It’s cases would swell just enough ahead of the belt to where I couldn’t size them enough to chamber easily unless I was pushing the shoulder back waaayyy too much. I found two solutions. The first, and the one I thought worked best was I took a standard .257 Wby full length sizing die and had the top of it cut off where all it could size was the body. This allowed me to screw the die down far enough to size the area just ahead of the belt sufficiently for good chambering. I then used an unmolested die to bump the shoulder .002” or so.

After that, I discovered and tried the Willis collet die. It worked too, but didn’t squeeze the area ahead of the belt down as much as my modified FL. die.

John

Maybe, but I`ve found that problem in once fired stuff picked up at the range. I also bought some "once fired" 7 Wby brass. Ejector marks on the case head showed it was fired at least three times. The belts on some, not all, of those cases were expanded. So were the primer pockets. I got took on that deal.
I couldn`t chamber, after sizing, some of the range pick up stuff in 7 Rem mag. Smoked the head and belt area, and saw the problem.

Have a friend with two M70's chambered in 300WM. One of the rifles has a rather oval shaped chamber, and resized brass won't fit in the other rifle. After 4-5 firings resized brass wouldn't fit in the oval chambered rifle either. This is the die he bought to address the problem and now the brass will fit either rifle.

As others have said it doesn't seem to be common but when it happens that die appears to be the answer.

Don’t know if I gained anything. But the Barrel I put on it was a match select. Trying for the best accuracy possible.
And I’ve been loading for belted mags since 1969. Hasbeen

Arky, get the die. I think that’ll fix your issues pretty quick. Sounds like a nice rifle and a good shooting 7 Rem is a blessing in my opinion.

Update

Traded 500 small pistol primers for LRM primers. New scope bases, rings, and mounted an old VariXIII 3.5-10X 40 on the rifle.

Zeroed at 100 yards, sub minute with Hornady 139 SST and Hornady 139 Interlocks on top of H4831 in RP brass. This is the first time resizing, the brass so time will tell if I need the Collet Die.

Shot a nice fat doe the next day at about 130 yards with the Interlock.

Not a bang flop, but only ran 20 yards.

I shot and hand loaded for a 7mm Remington magnum for years all I ever did was size with an RCBS neck sizing die I was loading full tilt...1960s 3 lug Sako action with a 24"Shilen air gauge barrel. I used new Winchester cases stuffed with Reloader 22 pushing a 140 gr. Nosler BT 3325 fps (5 shot average).

I never reloaded any cases past 4 times and I never experienced any problems.

"I never reloaded any cases past 4 times and I never experienced any problems."

I, probably will not either. If not for problem the guy I sold the rifle to I would sell this rifle.

I, cleaned it, rubbed it down put in a gun sock, back to being a safe queen.

Wish I hadn't sold mine it's one of my favorite cartriges.

I have one and use it a lot. I like the go no go at the top to see if they need above the belt sizing. Several months ago I purchased 250 Winchester 7mm Rem. Mag. cases from the classifieds here on the fire. The pressure barrel these were fired in was way over sized and the primer strikes were way to one side. I sent Chad an email and called his attention to the off center fired cases. His response was OK thanks. I ran them through my Redding FL dies and they failed the go side of the above belt resizer. I borrowed a friend's RCBS dies and that didn't make any difference. I ran them all through the above belt sizer and now all are in spec and useable. I'm glad I have it. YMMV