Belted cartridges——is there really a difference with their accuracy
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JeffG
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Belted cartridges——is there really a difference with their accuracy
Ya, when reloading, if you screw up the headspacing and size them wrong they shoot terrible.
Ya, when reloading, if you screw up the headspacing and size them wrong they shoot terrible.
earlthegoat2
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A belt adds a complication. Maybe so slight as to barely be perceptible but it is there.
Since manufacturers have basically proven its existence is useless and even a hinderance to performance these days, it is probably best to be avoided if it is practical to do so.
All that said, average shooters will never notice.
Since manufacturers have basically proven its existence is useless and even a hinderance to performance these days, it is probably best to be avoided if it is practical to do so.
All that said, average shooters will never notice.
OP
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High Plains
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The long, sloping case of the 375 H&H had such a shape to hold large amounts of the string-like pieces of propellant available when the cartridge was developed. I think cordite was the chosen propellant. The 416 Rigby had the same type of stringed propellant but more of it and in larger diameter case with enough of a shoulder to not need a belt. The belt ensures proper headspace, which aids in easy case extraction. The long 375 case probably wouldn’t come out so well given it’s lack of much of a shoulder. The 7mm Rem and Weatherby cartridges I use do not have accuracy issues.
old heeler
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Carlos Hathcock won Won 1000yd Wimbledon Cup with Win 300mag.
https://www.thefreelibrary.com/White+feather-a0436438854
https://www.thefreelibrary.com/White+feather-a0436438854
The old British magnums (300 H&H, 375 H&H) were sloped like that to prevent them from sticking in the chamber on sweltering African days, given the powders available. Extraction needed to be as easy and as smooth as possible when something really big was trying to stomp or bite you. On top of that, the 375 H&H didn't have much of a shoulder to begin with. As you stated, the belt was there to provide positive headspace. Some of our cartridges could definitely use a belt today. One that comes to mind is the 35 Whelen, which also lacks an adequate shoulder.
Incidentally, a lot of the bigger cartridges, 400 Jeffery for instance, were loaded to a lower pressure for use in the heat of Africa. A rimmed cartridge that stuck in the chamber of your double rifle and had the rim torn off by the extractor would not make for a pleasant day.
DM~
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With the size of the extractor on a double rifle with rimmed cartridges, I've never seen a rim torn off!
DM
DM
Bacon buster
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My 300 win mag consistently out shoots me. I can hold .3s pretty consistently and occasionally .2s depending on my coffee breakfast schedule. How accurate does a gun have to be before it is no longer the deficiency
JCooperfan1911
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There’s no such thing as “30mm Vulcan”.
earlthegoat2 said:
The belt adds no complication to the user and none to the manufacturer either. We had zero problem at Remington making belted brass. I'm on 8 loadings of .375 H&H brass and more than that on some .300 WM brass. I'm not sure where you're getting your information that the belt is a hindrance. How so? Factory or reloads, there's no hindrance from the belt. Are there more efficient case options these days ... sure! The 300 WSM was supposed to replace the .300 Win Mag, but rifle and ammunition sales have shown unequivocally that the WSM never achieved it's intended goal. The 300 WSM is an excellent cartridge but so is the .300 Win Mag which actually offers some tangible advantages over the WSM.
I bought a .300 WM last year and will happily buy more belted offerings without a second thought.
lysanderxiii
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I think you'll find that bottle-necked belted cases last a few reloadings longer than rimless bottle-necks.
.308 Norma
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Really? What about rimmed bottle-necks, such as 30-30s? Just curious.
lysanderxiii
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Because the the way the case headspaces in the chamber, belted, rimmed , and semi-rimmed will have a space forward of the shoulder. When the propellant is ignited the pressure will pin the sides of the case to the walls of the chamber and balloon the shoulder of the case into the gap without without placing much axial strain on the case walls.Really? What about rimmed bottle-necks, such as 30-30s? Just curious.
In contrast, a rimless cartridge case will seat with the case shoulder in contact with the chamber shoulder and the gap between the case head and breech face. When the propellant is touched off and the pressure builds, it will pin the body of the case in place and push the case head to the rear. Since the thin section of the case will grip the most, and this is the forward 2/3s of the case body, all of the stretch will be confined to the rear 1/3 of the case.
Now, the the gap in any case is only about 0.005 to 0.006" so the stretch isn't much, but after multiple reloadings, it adds up.
The there is "drive in", the fact that the headspace is measured to the back of the locking lugs, but the bolt does not stop until the front of the locking lugs come in contact with the receiver. Drive-in will shorten the case of a rimless bottle neck, even in a manual bolt action, however, with rimmed, semi-rimmed or belted cases the rim or belt has enough strength to prevent measurable shortening.
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.308 Norma
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Oh, okay. Thanks lysanderxiii!
I actually do load for a couple of belted, bottlenecked, rimless cartridges (my 308 Norma Mag and my wife's 7mm Rem Mag), but after the first firing, I force them to headspace off their shoulders by not setting their shoulders back anyway. The only rimmed, bottleneck rifle case I load for is my wife's old 32 Winchester Special, and she doesn't shoot that often enough to worry about how long the cases last. Besides, it's a Winchester 94 (lever action) and I'm not sure how well just neck sizing would work for that.
I see your hypothesis, I grant many valid points, I have yet to see enough physical evidence of tested hypothesis to prove theory or fact. While this does make sense, there are enough variables in this hobby/addiction/sport to have further questions; eventually we could even delve into neck sizing vs partial vs fl sizing in regards to case life. Is there more substantial data to support this claim? (It fully makes sense I'm not arguing, just curious, have gotten a GOOD SEVERAL loadings, 7+ to 10+, out of some pretty high pressure rounds, close to at or above book max in several cartridges, without belts, and if belts provide even better case life consistently, I'm very intrigued.)
earlthegoat2
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Fair enough and all your points are valid.
I call it a complication the same way I would call a pothole a complication. It is there and it will not prevent me from where I am going but it is there and it would be better if it weren’t.
If someone has to resize brass to to headspace on the shoulder all the while having to make sure the belt doesn’t interfere adds a level of complication. It is slight but it is there.
The design is outdated even if outsells the updated design. The belt takes away case capacity and is a vestigial part of a cartridge now.
I agree that I may be overplaying this and it is probably off topic for the thread anyway as the question of accuracy was primary. Of which I will say there is little difference if any especially if each is provided with careful hand loads.
Don’t take this post to think that I mean all belted cartridges are useless and should not be produced anymore. I have a great love for the 257 Weatherby and would not trade it for a modern “update”.
lysanderxiii
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Melvin Johnson wrote a very good article on the "drive-in" phenomenon in an issue of "The American Rifleman" way back when. He actually measured how much shortening of the case was seen in several rifle types.
With just neck-sizing, careful chambering of the rounds, and using only the same rifle, there theoretically wouldn't be any case stretch beyond the first firing. Unfortunately, that only works with bolt actions, semi-automatics and straight-pulls require a more radial clearance, and unless you have specially made resizing dies, getting the required radial clearance will result in pushing the should back.
Archie
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As the owner of a .35 Whelen, I find that statement "curious".
This. Plus, the propellants that you mentioned were very hard on chamber throats. A rifle with an eroded chamber throat could, to a degree, still use the belt for proper spacing of the cartridge.
The original problem in that regard, from reading I have done, involves the original Nitro Express cartridges that were actually black powder numbers that made the leap to cordite. The rims of these cartridges were thin. When used with a dose of cordite in extreme African temperature conditions, the case would sometimes stick in the chamber and the thin rim would be torn off upon extraction. I doubt that any of us today have actually used one of these cartridges, say the .450/.400 3 1/4 inch Nitro-for-Black. Later cartridges were designed from the outset with thicker rims. See page 550 of the 14th edition Cartridges of the World for a description of this problem.
Never shot one myself, but I have read that it is a very effective big game cartridge. The comment about the shoulder refers to printed references referring to the same. The one I have in front of me at the moment is page 151, 14th edition Cartridges of the World.
As a utilizer of neck sizing, I can tell you that there's still some stretching going on because I still have to fl size and trim every 4-6 firings. I like the proposed ideas, I'm just not fully sold I reckon.
Nature Boy
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Exactly. Everyone FL size their brass. Some just do it more frequently than others
Offfhand
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Ben Comfort won the Wimbledon with a rifle built by Griffin & Howe and shooting factory ammo loaded by Western Cartridge Co. His win was much protested by shooters who felt the match was only for .30/06 and finally resolved in his favor after hours of debate. Within days of the event, Winchester announced their M-70 target rifle in .300 H&H caliber, which became the rifle and cartridge to beat until 1960's. When I was with the AMTU during my military career we still had and competed with those rifles and factory loaded .300 H&H match ammo. During that time we switched to the then new .300 Win Mag. We then competed with handloaded .300 Win Mag, always using NEW brass. And using the same ammo in each of our rifles. Which obviously was headspaced on belt, not shoulder. We won lots of matches and for years, even today, the .300 WinMag is a staple in Wimbledon type competitions. Attached are two .300 WinMag rifles I've used in such competitions, with both iron sights and scopes. I've never won the Wimbledon, which was a longtime goal, but was twice in the shoot-offs. Was also on record setting two-man team at 1000 yds, firing 7mm RemMag, another belted caliber. Also pic of some Remington .300 H&H match ammo, which was typical fare when the .300 H&H ruled the ranges.
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