Digital Headspace Gauge
Adjusting your loading die to deliver exactly the right headspace length can be a real trial-and-error process. Ideally, the shoulder of the case you're reloading should be set back a maximum of .002 inch. However, bumping your die with the shellholder may push the shoulder back too far for some rifle chambers.
Resizing dies are made to make handloads fit in the very smallest chamber
designed for a particular cartridge. This means handloaded rounds will always be smaller than your rifle's chamber. What's more, rifle chambers
are usually sized to accommodate the largest factory loads produced by commercial ammunition manufacturers. Machinists call this "acceptable
- Clair Rees
(September, 2002 Issue)
A Collet for Belted Magnum Cases
Belts on the belted magnum case were put there for headspace control and not for strength, as is sometimes claimed. Once the case has been fired, the life of the case and perhaps accuracy, can be improved by headspacing off the shoulder rather than the belt. This is easily done by backing out the sizing die so that it doesn't set back the shoulder any more than just enough to insure that the case will chamber freely in the gun.
Because of the taper in ordinary resizing dies, the back end of the case (at the pressure ring), is usually left slightly larger in diameter than desired. Innovative Technologies has come up with a clever solution: a collet-type resizing die that sizes the body of the case right up to the belt.
In use, the die body is screwed into the press from the bottom. A fired case is dropped into the top of the die. If it drops in freely to the belt, there's no reason for any further sizing. If it fails to drop in freely, the case is removed from the die body and the collet is slipped over the case until it bottoms on the belt. The case and collet are then pressed up into the die body in the usual way. The collet is squeezed against the case by the die body and resizes it. When the case is removed from the die body the collet comes out with the case and is then slipped off.
Neck sizing, and any required reforming of the shoulder, is then completed using the regular dies for the caliber. All the basic belted magnum cases can be sized using the same collet. This collet die works very well and is a very useful accessory to the reloader of the belted magnum cases.
- Craig Boddington
A Magnum Sized Project
I had an interesting adventure a few years ago, while on a deer hunt in north Florida that made me consider buying my first magnum rifle. We always need some reason to justify getting "another" new rifle. This is about as good a reason as I could think of. This is a common scenario, so if it sounds familiar to you then maybe you can use this story to justify getting another rifle too. This adventure really did get me interested in hunting with a belted magnum caliber and that opened a whole new set of reloading problems to solve.
I was waiting in the most strategic location, overlooking a scenic view across a vast, wide open clear-cut. We scouted this area the day before and found that it was totally covered with fresh deer tracks. This would, more than likely, require a 400 to 500 yard shot. I was confident of my laser range finder, trajectory chart, and my reliable .308 Winchester. I really prefer hunting at long range. For one thing, your scent is not quite as much of a problem. Just as we were coming to prime time (late afternoon just before dark), I saw a nice 6 point buck that I was looking for, except that he wasn't where he was supposed to be. The buck was 40 yards to my left and still in the woods. This was an easy shot that I just couldn't refuse. There was no chance that this deer would run off and cause a long search in the dark. The crosshairs were locked on as I squeezed the shot. BLAM .... Well, that deer took off running like a burnt boot. I remember saying out loud "No way!" At that distance, how could he run away from this one? I knew that the shot was placed perfectly and that he wouldn't go far. We recovered that deer 50 yards away, deep into the thickest under brush you ever saw, and sure enough ... it was a perfect shot right through the heart.
That type of experience makes you wonder about taking really long shots. It would sure stack the odds in your favor to use a magnum on extreme long-range shots. Most serious long range hunters know that the velocity of their hunting ammo beyond 300 yards is not exactly spectacular. If you're taking shots at that distance without using a magnum, you could be spending more time in search parties than you might like. Tracking a wounded deer through Florida's swampy terrain, in the dark, is no picnic. Even a 50 yard search can become an almost impossible mission. I prefer to take one long accurate shot and avoid all of the searching around in the dark. The 300 Winchester is now one of my favorite cartridges for the long shots. There are also a few good Weatherby Magnums that I like.
Last year, I accurized a Browning 300 Win. Mag A-bolt Composite Stalker that has become my long range deer blaster. Little did I know then that this magnum cartridge would be the start of an expensive two year project. It started while developing a good load for say ...400 to 500 yards ... I know a great place in north Florida where it is still possible. Almost any lightweight hunting rifle in a magnum caliber will generate plenty of recoil. Several years ago, I experienced this phenomenon on a hunting trip where I was almost knocked out of my tree stand from the recoil of a magnum rifle ... and it would have been a long way down. It seems that you seldom have the luxury of shooting from a comfortable position when the critical moment comes along.
I wanted to see if an accurate, effective hunting load could be made for the 300 Winchester Magnum that would shoot as flat as possible with reasonable recoil. I started off by reloading at the range, like I usually do, to see how the pressure signs increase as the load develops. After a few trips to the range, I decided to go with a very unusual combination that would accomplish all of my objectives. The load uses a 130-grain Speer hollow point bullet, Federal brass, 77.5 grains of IMR4350, Fed210 Match primer, and the overall length is 3.230". This has a short overall length and will easily feed through the magazine, but it has an enormous jump to the rifling. The important thing is that this load will shoot consistent MOA groups in my rifle, and this particular bullet travels at 3420 fps. The 130-grain Speer bullet was originally designed for varmints, but it really performs well on deer at 200 to 500 yards. It's a great bullet that can only travel this fast with the help of a magnum cartridge. This load is a flat shooter but quite wind sensitive beyond 300 yards. However, during early morning and late afternoon hunts in Florida, wind is not a problem. The recoil is very mild with this load and it's a pleasure to shoot. In fact, the recoil feels similar to shooting my .308 Winchester. I found this to be a promising handload, so I planned to return on the following weekend with a few dozen rounds for the final test.
I was feeling pretty darned confident that I was going to have real success when I returned to the range ..... what could go wrong? We all know that feeling. When I headed out to the range the wind was as still as I've ever seen it before and there was blue sky in all directions. Then, I arrived to find that I had the whole rifle range to myself. God was with me for sure. I took my time and got everything set up to shoot my first group. That's when I found that my precious handloads would not chamber. What a bummer! This brass was only fired twice before and it was resized with the same Full Length resizing die that I had been using, and it was made by one of the most popular die manufacturers. That's when I remembered one of my shooting buddies tell me that he didn't reload belted magnums, because the cases would swell up so much that they could only be reloaded 2 or 3 times before the resizing die would fail to remove the bulge "just above" the belt. He also said that belted magnums could swell up and increase the diameter of the belt itself, although he said that he has never seen it happen that way. Well I whipped out my calipers to see exactly what was causing me to loose such a good day at the range.
The problem was a slight bulge "just above" the belt. My cartridges had swollen to .514" after the second loading of my cases. This dimension starts out at .507" on unfired Federal or Winchester cases. The "standard" case dimension in this area is .511" according to all of my reloading manuals. The minimum SAAMI spec chamber size, in this area is .5136" (and it's the same for 95% of all belted magnum cartridges). I later tried using several types of dies and the same thing just kept happening after the second or third reloading. This resizing problem only occurs with belted magnum cases because of their unique case design.
I later found that this problem has been
around for over 50 years and lots of shooters are familiar with the case expansion problems that occur "just above" the belt.
In order to reduce any given area of your case, a FL resizing die needs to travel about .100" beyond contacting
that area, just to reduce the case diameter by .001". Belted cases prevent conventional resizing dies from
traveling far enough down the case. These cases soon develop a slight "bulge" around the pressure ring (usually after
just 2 or 3 firings) and when that happens, the case is useless. This case bulge happens during the reloading process - not
when it's in the chamber. Many shooters have discovered this problem the same way I did . . . . when their handloads
begin to stick in their chamber or when they no longer chamber at all.
Remember the nine-month project that I mentioned earlier? I found that there are a lot of shooters out there that are aware of this condition with belted cases. Most of 'em found out about it the same way that I did. There had to be a solution, so I called Bob Blane at Sinclair International. Most of us know that these people are real serious shooters and that they can supply us with every type of reloading tool and widget that you can possibly imagine. He told me that "If you're shooting a belted magnum cartridge, that's what happens ... period. There's nothing that you can do about it". Gadzooks ... I might have actually come across something that really needs to be invented!
I tested so much at the range that some people may have thought that I lived out there.
Belted magnum cartridges have existed for over fifty years with this problem. There must be a good sized market for a new type of resizing die that would solve this reloading problem. This would have to be a resizing die that could fit in any single stage reloading press. With a little help from the SAAMI, I was able to examine the exact chamber and case dimensions for all belted magnum cartridges. I discovered that if such a die could be made, it would work on ALL of the popular belted magnum calibers including: .257 Weatherby Magnum, 6.5 Remington Magnum, .264 Winchester Magnum, .270 Weatherby Magnum, 7 x 61 Sharpe & Hart, 7mm Remington Magnum, 7mm Weatherby Magnum, 7mm STW, .300 H & H Magnum, .300 Winchester Magnum, .300 Weatherby Magnum, .308 Norma Magnum, 8mm Remington Magnum, .338 Winchester Magnum, .340 Weatherby Magnum, .350 Remington Magnum, .358 Norma Magnum, .375 H & H Magnum, .416 Remington Magnum, .458 Winchester magnum and several wildcat belted cartridges. I experimented with several different designs of collet resizing dies and I resized all of the different belted calibers that I could get my hands on. I also fired 300 Win Mag cases that were fired in different rifles to measure the effects of cases fired in a wide variation of chamber sizes. I fired mild loads and hot loads, even a few "dragon" loads.
After making 4 expensive prototype dies, the project evolved into a totally new type of resizing die. The last prototype resizing die required a specially designed collet that expands on both ends. Then I had to overcome a problem that would reduce the force required to operate the press handle. Critical angles were measured using an optical comparitor and measurements were taken into consideration that produced smooth press operation and insured that it would work on more than 20 different belted cartridges .... with using just this one die. The material selected was D2 because of the hardness and resistance to rust. The heat treating took considerable time to determine the effect on the final dimensions. To insure consistent tolerances I wound up making one final machine operation after the die was hardened. The final product required a jillion man-hours and all of the determination that I had before it was ...... perfected.
I received lots of help
from Greg and Ron
They helped make this "mission impossible" seem quite possible. Greg runs a very honest business with experienced machinists and a fully equipped CNC machine shop. Without their help I doubt that I would have ever completed this project. When the new resizing die was finished, it looked beautiful and it worked like a charm. Now I can reload belted magnum cases more that 20 times with hot handloads, and the cases are still looking good. This new design of resizing die reduces the case diameter "just above" the belt and does not affect any other dimension. It is used after the regular resizing operation. Belted magnum cases now have an extremely long life. The primer pockets are "just barely" starting to loosen after 20 firings so I tossed 'em at that point. The necks had barely started to harden, but there are still no signs of cracks. That's a great life span for such expensive brass!
I was so impressed with the end result, that I now have a patent pending for this tool. I call it the "Belted Magnum Collet Resizing Die". I really bet the farm on this idea. My shooting buddies all wanted to know when they could get their hands on one of my resizing dies. They reminded me that "It was taking too long ... and after all, nobody lives forever"! In case you have the urge to invent something it's a painfully slow process. Here is a short list of things to overcome before you can make something like this available to the public:
With a little luck I'll find some distributors to help me sell 'em before I go completely broke. The picture below shows the whole unit. It includes an unusual looking resizing die, a precision ground collet and the locking collar. All parts are made from stainless steel, and the die itself is hardened D2. The die and collet assembly reduce only the outside case diameter just above the belt. We're only talking about reducing a half inch of the case, by a few thousandths of an inch, but it makes all the difference in the world. The force required from the press is slightly more than resizing a .308 Winchester with a conventional full length resizing die.
This die can be
used on any single stage press. Unlike conventional
Operating Instructions (Updated version)
The biggest handloading problem with belted magnums is now easily solved. Those new, short, fat, unbelted, magnum "barrel burners" will stand a little shorter now!
- Larry Willis
There are now over 6,000 shooters using our Belted Magnum Collet Resizing Die worldwide. The cost of manufacturing this unique die is quite high. So, if you would like one . . . . don't wait. They may not be available forever.