I was reading a artical on reforming the shoulder on belted mags to head space on the shoulder so as to stop the case stretching just in front of the belt leading to shorten case life.He goes on to say to reform the shoulder so that the cartridge headspaces on the shoulder.What i would like to know as where would I get a tapered neck expander for case forming,I emailed RCBS about this and they don't seem to know what I am talking about.anyone done this or is doing this? The artical is in the July 2010 Shooting times,by Allen Jones under Going Ballistic
extending case life in belted mags
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I don't know what you aked RCBS for either.
Having cases head space on the shoulder, be they rimmed or belted, is nothing new. It is simply fire forming a case to make it fit the chamber. In order to do this, the loaded round must be held firmly against the shoulder, pushed forward, when it is fired,
An ideal way to do this is to load, a lighter charge than full power, if you wish, and load a bullet, preferrably a cast bullet, far enough out that it pushes firmly into the rifling when it is chambered. After firing, thecase will be a perfect fit in the chamber of that rifle. From here on, just neck size it, or, best of all, set the sizing die so it just kisses the shoulder, without actually setting it back, any.
I agree with H4831. If this sounds too complex, just blacken a case fired in your rifle and slowly lower your resizing die until you just contact the junction of the neck and the shoulder and lock it there. You may in real life be headspacing on both the shoulder and the belt, but I doubt it. By doing this you now headspace like a regular rimless case instead of the belt, but no big deal.
Your case gets formed to the chamber every time you fire the gun. The problem comes in when you resize it. Most FL dies push the shoulder back again so there is extra clearance (headspace on the shoulder).
One way to avoid this is to just neck size, or do a partial full length size. I have done the partial full length on my .264WM (belted case) for a few loads now. I stroke the press so only 2/3 of the neck is sized with the FL die. The bolt close is slightly stiffer but it still closes easily. Not sure how long I will get away with it.
Another way, which will work is to measure the fired case base to shoulder dimension, and adjust your FL die so it moves the shoulder 0.001-0.002" back when you size it. Hornady makes a gauge to do this.
One way to avoid this is to just neck size, or do a partial full length size. I have done the partial full length on my .264WM (belted case) for a few loads now. I stroke the press so only 2/3 of the neck is sized with the FL die. The bolt close is slightly stiffer but it still closes easily. Not sure how long I will get away with it.
Another way, which will work is to measure the fired case base to shoulder dimension, and adjust your FL die so it moves the shoulder 0.001-0.002" back when you size it. Hornady makes a gauge to do this.
Just fo clarify my first posting.
The OP sounded like his rifle had excess head space and was looking for a way to counteract it.
A factory round, or a handload from new brass, will be stretched, therefore being damaged, on first firing, to a greater or lesser degree, depending on how much headspace the rifle has. Thus, the first time fired brass will have a certain amount of damage, prior to first resizing, including just neck resizing.
My first post showed how to keep new brass in perfect condition, right from the first firing.
The OP sounded like his rifle had excess head space and was looking for a way to counteract it.
A factory round, or a handload from new brass, will be stretched, therefore being damaged, on first firing, to a greater or lesser degree, depending on how much headspace the rifle has. Thus, the first time fired brass will have a certain amount of damage, prior to first resizing, including just neck resizing.
My first post showed how to keep new brass in perfect condition, right from the first firing.
I'm afraid I don't agree. You can oil the cases, or put false sholders on the case, or do a significant jam with the bullets, but once you pull the trigger the brass stretches to fill the chamber. It will stretch the most right before the head. The best you can do is only let this happen once.
If your initial firing is done in such a way to keep the case tight against the boltface when the trigger is pulled, the case will suffer less stretch near the head than with any other method. What H4831 says is correct. Eagleye.
If starting with new brass, the neck could be expanded up, and then the case partially sized, to leave a false shoulder. This will keep the casehead back against the boltface for the first shot, and prevent the case from stretching just in front of the head. Is that what you were asking RCBS?
If a case has been fired, necksize it if it chambers freely, or partially size it until it does.
If a case has been fired, necksize it if it chambers freely, or partially size it until it does.
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I have one, have used it lots and yes it does.
I haven't had any worse luck with case life on belted cases than with anything else. Just because a chamber for a belted case can potentially be cut sloppy doesn't mean that it will be. I've got some long chambers on beltless cases too.
The time comes, in a reloaders life where he realizes that although many gun problems can be fixed on the reloading bench, they shouldn't have to be.
The time comes, in a reloaders life where he realizes that although many gun problems can be fixed on the reloading bench, they shouldn't have to be.
I'm sure it does. However, there is no need for one, unless your cartridge does not fit in your chamber. This is very unlikely to happen unless you are using brass which was shot in another chamber. Using the Willis die on brass from your own gun in my opinion is a waste of time and detrimental to accuracy. It is like bumping the shoulder back when you don't have to.
Two possibilities.
1. Neck out to a larger diameter, and then size with a false shoulder so the new case is a tight fit. [Bolt closes with some difficulty] When a loaded round is fired, the case stretches to fit at the shoulder area, not down by the web.
2. Seat a bullet so it jams hard into the rifling. When fired, this case will do exactly the same, stretch at the shoulder area to take up the space, not at the web.
I had a 7mm Mag Ruger #1 that had a very generous chamber. If you fired a factory round, or a reload with new brass, it would stretch enough at the web area that you could see the shiny "ring" where the stretch had occurred. Cutting a case lengthwise after 1 firing revealed a distinct thinning of the brass just ahead of the web. However, If I used either of the two methods mentioned above, the shiny "ring" was absent and when cut, the case showed no thin section near the web. By not pushing the shoulder back on subsequent firings, brass life was as good as in any other 7mm Mag rifle. Firing the brass with the visible ring would result in case separations at the 5th firing or so. After reloading for 45 years, I have learned what works and what does not. Regards, Eagleye.
I guess our experiences differ. Have been loading a .264WM in two different guns for 45 years as well. Get about 20 reloads without annealing. The cases die from neck splits, which likely could be prevented by neck annealing. Never had a head separation, although I do get the shiny ring on the case OD.
The issue I have with the little tricks is that with the pressure in a cartridge building very rapidly, it acts in all directions. The bullet is not going to leave the case without the cartridge head being hard back on the bolt, with the brass stretching in all directions.
In any case, my thoughts are that the head separation problem requires two things; excessive headspace, and repeated full length resizings where the shoulder is pushed back over and over again. The worse the excessive headspace the fewer cycles it takes.
The issue I have with the little tricks is that with the pressure in a cartridge building very rapidly, it acts in all directions. The bullet is not going to leave the case without the cartridge head being hard back on the bolt, with the brass stretching in all directions.
In any case, my thoughts are that the head separation problem requires two things; excessive headspace, and repeated full length resizings where the shoulder is pushed back over and over again. The worse the excessive headspace the fewer cycles it takes.
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Something is wrong with your gun if you cannot chamber a cartridge after it has been fired 4-5 times in the same gun, assuming you are neck sizing it, or if necessary FL sizing it, with a minimum shoulder bump. I've loaded belted magnum cases up to 20 times with no issues at all, unless I try to switch brass from one gun to another. And even then it is usually a neck split that kills them, not that the case is "bulged".
I agree whoelheartedly with the last paragraph here. I expect 20 reloadings from a case, belted or not. The point is, that if a case is already tight against the boltface, it cannot stretch any farther in that direction, so it moves forward instead. When that happens, it does not thin the case near the web. I've proven that by sawing many cases apart after firing them under varying circumstances.
BTW, 264 Win Mag is one of my favorites. I've owned a half dozen or so over the past 40 years....even had a couple of custom rifles built in this chambering. Great open country rifle for anything up to and including Elk. Eagleye.
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you are fantastic at diagnosing problems with other peoples rifles with so little knowledge. are you a psychic? i will explain it to you if you care to understand. if you have a rifle with a particularly tight chamber, and FL size for it with a set of dies that are particularly loose, you are unable to properly size the area just ahead of the belt. this can, and does in some cases, lead to the condition sometimes known as "belt bulge" which will prevent cartridges freely chambering after only a few firings, especially with hot loads. this is why the belted mag die was invented, ron. but i guess if you have not seen this happen then it must not exist right?
