American army gets a hot new cartridge

[winnie_the_pooh]

They get a new cartridge after 65 years. But what a choice. This is the cartridge you get for your army when ,if you need money you just walk down to the printing press and print a trillion dollars.

[timmy]

This could very well be the future of all cartridge construction someday.

I would imagine that some folks considered our present brass cartridge cases extravagant at the time of the Franco-Prussian War, when cartridges were made of paper and the primer was internal, struck when a needle-like firing pin pierced the paper case and struck the primer buried in the black powder charge. Cartridges could be made at the kitchen table in those days!

The key issue I see here is the large increase in operating pressure, from 66,000 psi to 80,000 psi. It is the approximate doubling of pressure that allows the 9 mm Luger to develop similar energy levels as the much larger 45 Auto, for instance. The higher pressure of the 30 Super Carry allows a slightly longer cartridge than the 32 Auto to produce performance about equal to 9 mm Luger. This increase in the power of smaller cartridges relies on the improvement of bullets to take advantage, but since this has happened over the past couple of decades, we have the opportunity to have higher performing rounds.

For the military, the advantages are greater performance from short barrels, and my understanding is that they wanted better performance for dealing with body armor.

My personal view is this: this method of cartridge manufacture could well supplant our current brass cases with only a small increase in cost. Since these new cases with a stainless steel head are supposedly reloadable many more times than brass cases, this seems like an advancement to me, except that new dies are probably required to work with the new cases, and I would not welcome the need to purchase a new set of dies, or at least the sizer dies for each cartridge set. I have enough brass that it doesn't seem as if I'd need to upgrade cases or dies, at least not for quite some time.

From the performance perspective, I'm probably not affected by this, either, as I am almost totally a cast bullet shooter, and the extra performance provided by the increased pressure would do me little good. Besides, so many of my cartridges are not likely to use this new construction soon, if at all.

For the civilian market, I do see one advantage: short heavy barrels can provide an accuracy advantage, and this cartridge was intended to provide 3000 f/s performance from a 16" barrel. No benchrest or long range barrels used today are this short, so there's one good thing.

Meantime, I am very happy that the world has been gushing love over the 6.8 mm / 0/277" caliber. I like it too, and appreciate knowing that the 270 in my safe is as modern as tomorrow.

[winnie_the_pooh]

This could very well be the future of all cartridge construction someday.

It most certainly will. However it would take some time to become affordable and widely available. This company also has what they call composite cased ammo.

[bbvideo] [/bbvideo]

[eljefe]

If 80k psi is sign of things to come in rifle ballistics, as well as composite cases, i wonder if the standard chrome lined barrels will do? Is there any mention of barrel life?

The Poms made .276 SA prototype after WW2, but succumbed to the Yank pressure to settle for the .308 and later, the .223

I guess the “1 mag 1 kill” ability of the 5.56 has proven itself many times over for such a sea change. ?

[eljefe]

https://www.army.mil/article/255827/arm ... n_contract

https://www.19fortyfive.com/2022/01/win ... gsw-rifle/

https://www.guntalk.com/post/vortex-xm1 ... ed-by-army

[partheus]

Winnie, how does this qualify as an advancement? If the steel head is all they've added, then what's wrong with steel cased rounds that abound already? Also, I see a slight gap between the head and the brass body. Could this be another go at the belted case theory (i.e. we need a belt coz the cartridge is so damn powerful)?

[winnie_the_pooh]

Winnie, how does this qualify as an advancement? If the steel head is all they've added, then what's wrong with steel cased rounds that abound already? Also, I see a slight gap between the head and the brass body. Could this be another go at the belted case theory (i.e. we need a belt coz the cartridge is so damn powerful)?

I am no expert on this. Timmy is the one who has the best chance of having a first hand experience of this ammo.

Us folks are going gaga over shoddily made copies of Spainish and English guns that were once made by companies that no longer exist or if they do, are not firearm manufacturers anymore

[timmy]

If 80k psi is sign of things to come in rifle ballistics, as well as composite cases, i wonder if the standard chrome lined barrels will do? Is there any mention of barrel life?

From what I've read, SIG has developed new powders for this round, which not only are faster burning (relative to 7.62 NATO) but also are supposed to improve barrel life over currently used powders.

I don't know anything more about the powders used or about barrel life than this, other than that the testing showed that barrel life was not objectionable and met the specifications provided.

I do know, when looking at modern powders, that new powders have less sensitivity to temperature and they have a positive effect against copper fouling, so there's no doubt that powders, like cartridges in general, cars, and airplanes, can and have been improved over time. I don't have any reason to think that powders that improve barrel life cannot be developed.

I also note that the muzzle velocity has not been significantly improved in the new round. Therefore, it would not be a factor in barrel wear. 3000 f/s is not an exceptionally high velocity, but what is groundbreaking is getting that velocity in a short 16" barrel.

Until such powders become available to civilian reloaders, we won't know much about its real properties in the field. Old curmudgeon that I am, my powders are Bullseye and Unique, both over 100 years old, and 4198 (both H and IMR) for rifles, and I think that these are post-WW2 powders. I do want to give Shooter's World Buffalo Rifle D060-01 powder a try, chiefly for the Martini Henry, though. This, as I understand it, is a powder offered by the Czech company Lovex and formerly marketed here as 5744, before that powder was switched to a different manufacturer. As I understand it, the original Lovex powder works best in the huge 577/450 case with appropriate loads, and is less position sensitive and offers more reliable ignition than the new 5744 or 4198. Hopefully, I will get a chance to find out.

The Poms made .276 SA prototype after WW2, but succumbed to the Yank pressure to settle for the .308 and later, the .223

Yes, this was more nearly a 7 mm round (0.282", as I recall) than a 6.8 or 270 cartridge (where 270 uses a 0.277 or 0.278 bullet).

My understanding is that the American choice was one of expediency. Firstly, the Americans wanted shoulder arms and machine guns to use the same ammunition for logistical purposes. (This was later given up with the 5.56 and with this SIG Fury round.) It must be recalled that, in those days, NATO forces faced an overwhelming disparity in force size, vis a vis the Warsaw Pact. For instance, at the end of WW2, the Soviet Union fielded about 300 divisions, while the USA had about 50 divisions in the European theater. After the War, most of the USA divisions went home, while the Soviet and Warsaw Pact armies remained huge and overwhelming in number. Anything in those days that could increase firepower, even if it wasn't the best, was the choice to deal with force size disparity.

Secondly, it is vital to remember that artillery, not shoulder arms, was still the most lethal force on the battlefield. Arguments over the ideal shoulder arm cartridge and, even more irrelevant, the ideal side arm cartridge, do have issues regarding relevancy.

Thirdly, the Americans were fielding the bulk of the men and equipment for the NATO response to the Warsaw Pact, and also had the largest infrastructure to support a war effort.

Fourthly, There was intense pressure on defense budgets during the Cold War. In the USA, for example, a huge political and inter-service fight was taking place over aircraft carriers for the Navy, versus B-36 and other bombers for the Air Force. Who was going to get nuclear weapons and the tactical versus strategic nature of those weapons were part of this fight. Nuclear weapons systems were being developed and funded, along with early warning systems like the DEW Line in Canada, meant to detect Soviet missiles launched across the Pole. Nuclear powered ships, especially submarines, were being developed at great cost in these times.

Defense budgets were stretched to the maximum, both in the real and in political senses. To hear the British whine about the absolute optimal shoulder weapon cartridge was not always the highest priority of these days, and being able to provide adequate logistics for an out-manned force in Europe, mostly across thousands of miles of ocean from the USA was in the forefront of military planning.

But, the proposed 280 British round was hardly the first attempt to address the question of an ideal shoulder weapon cartridge.

Back in the 1930s, the Americans developed several semi-automatic infantry rifles, the lead of which became the M1 Garand. (The Soviets were on the same track with their SVT 38 and SVT 40 semi-auto rifle, but it retained the 7.62 x 54r cartridge.) The intended cartridge for the Garand was the 276 Pedersen, which used a near 7 mm (again, 0.282") like the British post war development.

Today, those ignorant of history often criticize the US Army for choosing to chamber the M1 Garand in 30-06, rather than using the supposedly superior 276 Pedersen, but these folks ignore the fact that the USA, like most of the rest of the globe, was mired in a deep financial depression at this time.

The US Army Chief of Staff, General Douglas MacArthur, noting the huge stocks of 30-06 ammunition already on hand from WW1 and after, chose to spend the Army's meager budget on keeping as many officers and non-commissioned personnel as he could, as opposed to buying gadgets and marginal improvements in arms with the Army's budget. (You can see training films for the Army of the pre WW2 and early WW2 days, practicing with wooden guns, artillery, and trucks with wooden tank mock-up hulls to see the effects of the small military budgets.)

The key incident to relate here is MacArthur seeing President Franklin Roosevelt in the White House to argue for more military spending, and Roosevelt refusing. MacArthur ended by saying when the enemy had his boot on the throat of an American soldier and was preparing to bayonet him, he (MacArthur) wanted the curse on the American soldier's lips to be Roosevelt's name, and not his own. FDR told MacArthur that he could not talk to the President of the USA like that. MacArthur was so upset that, on leaving the White House, he vomited outside of the door.

This event illustrates the dire straits of military spending and budgets of the time, and which is conveniently ignored by those who, from the perspective of armchair warriors, debate the issue of the ideal cartridge for shoulder arms. MacArthur, in choosing to retain the human capital of experienced and trained troops to form cadres for the War sensible people knew was coming, was right to choose this path over the development of a new cartridge and building up the necessary stocks of ammunition for it.

But, the 276 Pedersen of the 1930s wasn't the beginning of this shoulder arm question, either.

It should be remembered that, after the poor performance of Enfield rifles, compared to Mausers, in the Boer War, the British Army began a search for a better infantry arm at the beginning of the 20th Century. The gun they developed became the P14 Enfield, but it was not originally chambered in 303. Instead, a 276 bore cartridge was intended to go along with the rifle.

EGB Reynolds, in his book, The Lee Enfield Rifle (an authoritative source on the subject) outlines the attributes of this cartridge:

The cartridge case was rimless.
The bullet. The core was led and antimony and the envelope was mild steel plated with cupro-nickel. Its diameter was .282 in. and it weighed 165 grains.
The charge was 49.3 grains of cordite M.D.T.
The overall length of the cartridge was 3.230 in.
Muzzle velocity 2,785 f.s. as against 2,440 f.s. of the .303-in. Mark VII cartridge.
Vertex of trajectory at 800 yeards, 5.23 ft. as against 9 ft. of the .303-in. Mark VII.

(Have you noted that the British selected a 7 mm cartridge as the ideal, after facing those Boers who used 7 mm Mauser rifles?)

The British, like the Americans 20 years later, were faced with the very likely outbreak of war in Europe, and elected to retain the existing 303 round, rather than adopting the new 276 round at such a critical time, when they viewed the time frame available to build up stocks of the new ammunition as being too short.

But like the Americans after them, they adapted the new rifle to the 303 round and fielded it, contracting American companies to build many of these 303 chambered P14 rifles for them. The British had done their homework well, for like the M1 Garand, the P14 was noted for its accuracy. Because of the shortage of 1903 Springfield rifles for the American Army when it entered the war in 1917, the P14 was modified on the Eddystone, Remington, and Winchester lines to use 30-06 ammunition and fielded as the M1917 rifle. So many of these "auxiliary" rifles were made that they far outnumbered the 1903 Springfield rifles in service. After WW1, the Americans discontinued the manufacture of M1917s and went back to their 1903 Springfields. Some felt that the M1917 was actually a better rifle than the 1903 Springfield. Remington continued making them as the basis of their Model 30 and Model 30S, and finally, their beautiful Model 720 rifles. (Remington also made 1903 Springfields, even through WW2 as the M1903A3, but chose to use the avaialble Enfield 1917 as the basis for their sporting rifle, rather than the available 1903 Springfield!) The actions of these rifles, unlike the 1903 Springfield and the M98 Mauser, have the strength and capability to be modified to accept the longer 300 and 375 H&H cartridges safely and reliably. I have long desired one, especially a 720, myself.

Nor was this the beginning of the idea to use small (sub-30 caliber) cartridges for infantry shoulder arms. The Italian, Japanese, Swedish, and Greek armies had all selected 6.5 mm cartridges for their forces before this time.

It is noteworthy that both the Italians and Japanese, noting the performance of their 6.5 mm rounds in machine guns, developed and began deploying larger calibers, efforts which in both cases were not completed before the outbreak of WW2. The Italians chose 7.35 Carcano, which was simply their existing 6.5 mm necked up for a near 30 caliber bullet, and the Japanese chose the 7.7 Japanese, which in performance was a rimless version of the 303 British round.

Returning to the post WW2 Cold War, the US Army wanted a shorter round than the existing 30-06 for use in automatic weapons, seeing the effectiveness of the shorter 8 x 57 mm Mauser rounds in the MG34 and MG42 German machine guns, on which German infantry squads were based. The superior performance of the German infantry during WW2, based around the machine gun, versus infantry squads fielded by everyone else, based around riflemen, convinced the Americans that automatic weapons fire was the key component of modern infantry, and that a shorter cartridge would be better than a longer one for designing a good machine gun. WW2 had also shown the need for a 30 caliber round for these machine guns (recalling the Italian and Japanese experiences) and logistics and force disparity pointed to a common machine gun and shoulder weapon cartridge. The advance of modern ball powder propellant made the same performance of 30-06 available in a shorter cartridge (7.62 x 51 NATO) possible.

Winnie, how does this qualify as an advancement? If the steel head is all they've added, then what's wrong with steel cased rounds that abound already? Also, I see a slight gap between the head and the brass body. Could this be another go at the belted case theory (i.e. we need a belt coz the cartridge is so damn powerful)?

I am no expert on this. Timmy is the one who has the best chance of having a first hand experience of this ammo.

If the steel head is all they've added, then what's wrong with steel cased rounds that abound already?

All steel is equal, but some is more equal than others, to paraphrase George Orwell. The Soviets pioneered the widespread use of steel case ammunition to enable supplying adequate ammunition stocks to their huge military without crippling their supply of copper and tin for making brass cartridge cases. They developed a soft steel case that worked well enough to meet that need. (Note here that a traditional Russian talent was, like India, metallurgy. Recall who invented and developed the Periodic Table!)

The stainless steel head of the SIG Fury round is much harder than the Soviet-developed steel case.

If you will note the cartridges in a new box of rifle ammunition (the ones that aren't nickel plated or polished) you will commonly see a discoloration around the neck and shoulder areas. This discoloration is the result of annealing, or making the brass of the neck and shoulder softer than the rest of the case.

Studying diagrams of a chambered round, it can be seen that almost all designs of firearms leave some amount of cartridge head exposed so that the extractor can do its job. For rimmed cartridges, the rim is all that's usually exposed -- that doesn't have any part of the cartridge case unsupported by the breech block, bolt, or chamber.

For rimless cartridges, some amount of the cartridge head is usually exposed. For instance, the "cone breech" of the 1903 Springfield and the Winchester Model 70 (pre-'64 style) leaves much more of the cartridge head unsupported than does the 1898 Mauser, with its flat-faced breech. For this reason (and others) the Mauser is said to be a safer action than the other two.

So, the neck and shoulder of a cartridge has to be relatively soft and "springy," so that it will be elastic enough to hold the bullet and expand without cracking when fired. Also the case needs to be slightly smaller than the chamber to be able to be inserted into the chamber reliably, but also needs to be "springy" so that it can obturate, or expand to seal the burning gases in the chamber. At the same time, the exposed part of the head needs to be "strong," so that the unsupported area won't blow out when the gun is fired. Just like some steel is strong and hard, and some is soft and tough, so the same brass case must have both toughness and strength in different areas. An annealed brass case works well for the pressures firearms work at today. But at higher pressures, these soft and hard at the same time properties must be maintained, and it looks like the composite case is a good way to achieve this reliably.

(A personal note here: I shoot a lot of surplus 7.62 x 54r steel cased surplus ammo, and a lot of commercial steel case 7.62 x 39 and 9 mm Luger ammo, and it all works quite well while being reasonable in price. However, it's not considered reloadable and is Berdan primed, which in itself is a huge pain to manage. The price of this steel ammo, both surplus and commercial, makes it a great choice, I think, but it ain't brass. It doesn't eject as reliably and its not reloadable. Brass is a really great metal for cartridge cases to this shooter and reloader!)

Sometimes a "rebated rim," as seen in the 284 Winchester, where the rimless rim is smaller in diameter than the cartridge body, is used to recess the case in the chamber, while still allowing the extractor hook to get hold of the rim. This permits getting the cartridge fully into the chamber.

Could this be another go at the belted case theory (i.e. we need a belt coz the cartridge is so damn powerful)?

This theory, usually propounded by such folks as the "Weatherby Crowd" back in the 50s and 60s, is simply false. The belt, in fact, lends no strength to the exposed part of the cartridge head, nor was that its purpose. Note that modern high intensity cartridges with 0.532" diameter heads have done away with the belt, so as to gain more diameter for the rest of the cartridge case and gain more powder capacity.

Let me try to explain the issue of the belt.

Firstly, we know that the rim of rimmed cartridges can cause feeding problems in magazine rifles (as it also does in machine guns, for other reasons). The British SMLE has some problems in this regard. The Russian/Soviet Mosin Nagant has an elegant way of dealing with this problem. For early semi-automatic handguns, "semi-rimless" cartridges were developed to deal with jam problems, such as the 32 Auto and 38 Auto, by John M Browning. However, the "semi-rimless" designation only noted a rimmed cartridge with a very small rim, and you know that a 32 Auto magazine loaded in a slovenly manner can experience jamming due to the small rim.

The rimless cartridge feeds quite nicely in magazine rifles, because there's no rim to lock with other rims.

Back around the turn of the Century, the British, famous for being big game hunters, noted the expense of rifles meant for big game, and coveted the more-than-two-shot capacity of bolt action rifles. But, they wanted a cartridge more powerful than was usually chambered in bolt action rifles, and higher powered cartridges usually had rims.

The rim of a rimmed cartridge is not just for extraction: It provides the "headspace" reference point for seating the cartridge in the chamber. It can only go into the chamber so far, before the rim prevents it from going in further. Headspace is a vital part of ensuring that the cartridge fits the chamber properly and doesn't split open when fired.

So, how to get the power of big rimmed cartridges, yet get the feeding of rimless cartridges in bolt action rifles made for dangerous game? (Here, I note, "for dangerous game." I'm sure you see the necessity for rock-solid reliable operation in rifles meant for dangerous game!)

Please note Holland and Holland's solution of the problem in this picture of the 300 and 375 H&H Magnum cartridges, shown along side the more modern 7 mm Remington Magnum cartridge on the left:



(click on the picture to enlarge)

The Remington cartridge on the left has a sharp shoulder angle. This makes the shoulder the headspacing reference point. The cartridge slides into the chamber, and when the shoulder meets the corresponding angle in the chamber, it can't go in any further.

But note the 300 and 375 H&H cartridges next to the 7 mm Remington: They have slight shoulder tapers and small shoulders, both of which cannot provide a reliable headspace point in the rifle's chamber. So, Holland and Holland added the "belt" to the base of their two cartridges. The cartridges space on the edge of the belt, the same as they do on a rim of a rimmed cartridge. (Actually, Holland and Holland had a rimmed version of both of these cartridges for double rifles.)

Now, the cartridges could headspace on the belt, while sliding into and out of the chambers of bolt action rifles reliably, just like rimless cartridges do.

So, why didn't the British just use a larger conventional cartridge? First of all, their dangerous game rifles were meant to be used all over the world, under widely varying climates. They could be used from the Arctic to the Sahara, from the Poles to the Tropics, and still operate reliably.

Secondly, the British used Cordite powder, a double-based powder (comprised of both nitro-cellulose and nitroglycerine). If you are a student of history and have studied the World War 1 Naval battles of Dogger Bank and Jutland, you will understand that Cordite was extremely prone to ignite at inconvenient times. Also, beside those battles, there were also other magazine explosions in British and other ships (like the USS Maine in Havana Harbor, several French vessels, and the Japanese battleship Mutsu). The important point here is that Cordite was unstable and subject to acting differently in different conditions. Besides the problems inherent in the nitro-cellulose and nitroglycerine composition, impurities in the powder introduced in manufacture of it made it even more unstable. But this is what Holland and Holland had to use.

You see that their sides are tapered much more than the Remington cartridge on the left. This taper makes the cartridge easier to extract after it has been fired and expanded in the chamber. Remember, the pressure generated in the cartridge when fired can vary widely due to the nature of Cordite. On a hot day, pressures can be extreme, while they are low on a cold day. Also, especially in humid conditions, fouling and dirt can cause extraction to be difficult.

So, Holland and Holland put a generous taper on their cartridges to allow them to be extracted easily, and they loaded them to somewhat lower pressures so that high temperatures wouldn't cause such high pressures as to make extraction difficult. They were engineered for RELIABLE performance, not MAXIMUM performance with the relatively unstable Cordite powder they had to work with.

For example, the 300 H&H cartridge was developed from the 375 H&H to provide 30-06 levels of performance in British guns used around the world. Americans took the 300 H&H, and, using American powders, took advantage of the size of the 300 H&H case to burn more powder and give higher velocity than the 30-06. Think this way: roughly, the 300 H&H can give the same velocity to a 180 grain bullet that a 30-06 can achieve with a 150 grain bullet.

After World War 1, American reloaders experimented with a lot of different cartridges. For example, the 30-06 was necked down to take a 0.257" bullet and became the 25-06. Charles Newton developed high power cartridges, too, taking advantage of the powders of the day, to design cartridges such as the 250-3000, the first commercial cartridge to give 3000 ft/second, and the 300 Savage. Savage used these short cartridges in their 99 Lever action rifles and their short bolt action 1920 to give performance from small cartridges normally available in larger ones -- the same trend we see today of getting more performance. The point here is that improvement has always been a part of firearms development.

After WW2, Roy Weatherby started developing his line of cartridges, based on the 300 and 375 H&H case. He took the taper out and made the walls of the case straight to increase powder capacity. He also had a theory about the shape of the neck and shoulders, giving this area radiused curves instead of sharp angles. Others did the same thing, and the basis for most of these cartridges was the 300/375 H&H case. Sometimes they shortened the case so that it would work with standard length bolt actions, like the 7 mm Remington you see in the picture. Sometimes they used the full length of the H&H parent case, like Weatherby did.

But the problem with doing what Weatherby did was that the Mauser M98 action, which in both military and commercial form, was the bedrock of custom rifle development of the day due to its strength, safety, and suitability for making up a sporting gun, was too short for the full length of Holland and Holland cartridges. To get these long cartridges to feed through the magazine of M98s, the ramp in front of the magazine had to be ground away and the magazine opening lengthened, and this weakened the area of the receiver that the lower locking lug of the bolt locked against. Hot loads with long H&H cartridges would eventually cause the M98 actions to fail.

Mauser, before WW2, had made a "Magnum" action that was longer than the ordinary M98 for these kinds of long cartridges, but after the war, the manufacture of these actions was taken over by the French company "Brevex," and these actions were not plentiful and were expensive, so they usually weren't the basis of most sporting rifles in the USA. Meanwhile, both Remington and Winchester had made their Model 721 and Model 70 long enough for the H&H cartridges.

This problem with the M98 Action caused Weatherby to design and produce his Mark 5 action, first by Sauer in Germany and then in Japan. It was able to take the long H&H based cartridges he used with no problems.

Weatherby was raised dirt-poor and designed his guns in a very gaudy fashion. They had "white line" spacers between the stock and exotic woods used on the end of the fore end and the between the stock and the pistol grip cap, and between the stock and the butt plate. Some wags called these white lines "bleach bottles" because they resembled the cheap plastic bottles used to contain laundry bleach. Various woods were used to inlay diamond shapes into the fore end, like a parquet floor. The stocks were given a shiny finish. In short, Weatherby made a product that reflected the tastes of a poor man who had become rich and marketed it as "the top of the line," although they never looked to me as luxurious as the guns of famous British makers.

(Weatherby also had big, prominent "Monte Carlo" humps on the butt stock, where British and classic American rifles, with narrower butt stocks, might have a discrete "cheek piece" raised area to get the "cheek weld" that aligned the eye with the sights when the rifle was snapped to the shoulder. With the widespread use of scope sights after WW2, gun makers designed stocks with a raised butt section, more in a straight line with the gun, to lift the cheek weld higher to align with the higher scope sight axis. Others made the cheek piece higher and wrapped it over the top of the butt stock, like a trap shotgun, so that the butt stock resembled a huge "canoe paddle." Ugh! I'll pass, but some obviously liked it.)

The cartridges of Weatherby, and of the later line of Winchester "Magnum" cartridges, the 264, 300, 338, and 458, and then the Remington 7 mm Magnum (which was extremely popular here, despite not really offering a whole lot more than the old 270 Winchester offered) became THE thing to have here. They were called "magnum" because magnum had been a title applied to an extra large and fat bottle of wine.

Because all of these cartridges were based on the original 300/375 H&H case, they had the same belt, even though, because they had relatively straight case sides and sharp shoulder angles, they didn't need the belt for headspacing, which was its purpose. The belt was there because that's what the case had before it had been reformed.

(Note of digression here: the 458 Winchester DID need the belt, because it didn't have any shoulder at all. It should be noted that the 458 Winchester, while very popular and capable, still had some problems with bullets and pressure early on, and many hunters preferred the old style 470 Nitro double rifles for this reason. The higher pressures of the 458 Winchester over the old British cartridges were not completely trouble free. Those "old beans" of Victorian and Edwardian Britain did know a thing or two about the problems they faced and what they did about it, after all!)

But many who saw the belts on these "Magnum" cartridges thought they were there for strength, because they weren't there for any other discernible reason. But, as you can see, it is a false reason.

Weatherby then went on to design his 378 Weatherby in the 50s. This cartridge, which was new, did have a belt, and the belt was surely not needed for head spacing. Just like his white line Bleach Bottle spacers, rosewood fore end caps and pistol grip caps, and diamond inlays, it was for decoration. The cartridge itself is similar in dimensions to the proven rimmed 416 Rigby, but since Weatherby had established a good business and was getting his cartridges made for him by Norma of Sweden, he could get the new cartridge designed any way he wanted. That was with a belt in this case.

Weatherby also used tricks such as a long "leade" or freebore, which is the section of the barrel just ahead of the chamber neck before the rifling starts, which has the effect of increasing velocity of the guns he advertised. What it does for ultimate accuracy is another matter, and I understand that Weatherby doesn't use long leades in their rifles now. current accuracy practice is to seat the bullet out of the case until it touches or nearly touches the beginning of the rifling, to launch the bullet into the rifling as straight as possible.

For the 378 Weatherby, as I understand it, he was forced to use the French/Mauser Brevex Magnum action. Later in the 50s, Weatherby introduced the 460 Weatherby, which was a necked up 378, after a wildcatter had paved the way by developing a prototype of it. The New Mark 5 Weatherby action also handled these cartridges without issue.

So, the end point of this long story is that belts on "belted magnum" cartridge cases did originally have headspacing and reliable feeding purposes as originally designed by Holland and Holland, but which became superfluous as people used the H&H cases for the basis of their own cartridges. Without a purpose, people began to associate the belts with cartridge strength and power, notions which are completely wrong, as demonstrated by new high-intensity cartridges of the last years using the same 0.532" rims, but without belts.

If someone has waded through all of this, I hope it helps.

[partheus]

Thanks for taking the time to write this, Timmy. Always a pleasure learning from you.

[MichaelJDay]

That is really great ammo
.

[timmy]

Thanks for taking the time to write this, Timmy. Always a pleasure learning from you.

Thank you, Sir, it is my pleasure. Having a gun conversation is always nice!

I should have added, in my writing, that other early attempts had been made to use a small caliber rifle, such as the Portuguese 6.5 mm, and also the US Navy also had adopted the 6 mm Lee Navy rifle for a time.

Winchester, for its new Model 54 bolt action rifle, used a shortened version of the 6mm Lee Navy case and added a rim of 12 mm (the common 0.473" rim diameter shared with 30-06, 8 x 57 mm Mauser, 270 Winchester, 45 Auto, and many other cartridges) to make the case semi-rimmed for its 220 Swift cartridge, which achieved a muzzle velocity of over 4,000 ft/sec. Oddly enough, the original research for this cartridge was done on a necked down version of the 250-3000 Savage, which became the 220 Swift's successful competitor, the 22-250. Ruger brought the 220 Swift back in its Model 77 bolt action, but the 223/5.56 NATO has pushed so many of these 22 centerfire cartridges to the side nowadays, as military cartridges so often have in gun history.

[partheus]

That's interesting. Speaking of the 556, I recently learnt that the Indian Army is phasing them out in favour of 7.62 NATOs for which a number of Sig 716s were purchased. I struggle to see the rationale for this. The 556 has proven itself in Afganistan, Iraq and remains in service in NATO countries.

[timmy]

Weren't the Sig 716 rifles for service along the LoC? My guess in that case would be for use in long range firefights, as the 7.62x51 would be better at, say 500+ meters than the 5.56.

I have not read anything regarding the military's rationale for this choice, though, so I'm only speculating.