<xmp><BODY></xmp>Ammunition: A Thought Experiment

Added 17-3-20
Updated 10-5-23

Ammunition: A Thought Experiment

.260 Remington Cartridges

In the west we have hundreds, possibly thousands of models of personal firearms. There are hundreds of different types of cartridge in use. The Soviet Union attempted to create an arsenal that used a single cartridge for each small-arms class, and a standard, single model of firearm for each class.

Theoretically, during the Second World War, the Soviets had one design of pistol, SMG, rifle, LMG and MMG, and a single type of pistol round or rifle round. In practice, the Mosin-Nagant rifle existed in a number of variants. Many older, but functional, weapons remained in service. These included Nagant revolvers, Mauser C96 variants, the PPD SMG and the M1910 Maxim. The “unofficial” PPS-42/43 SMG was also used in considerable numbers. The Soviets were quick to adopt an intermediate cartridge, adding another cartridge to the system and the AK-47 assault rifle, SKS carbine and RPK LMG. According to Modern Firearms.net a bolt-action weapon using the intermediate cartridge was also considered. I image this might have been a hybrid of the SKS and M44 Mosin-Nagant carbine.

Some video games offer you a wide variety of weapons, but simplify the ammunition to “pistol ammo”, “assault rifle ammo”, “sniper ammo” and so on. Many of these games ignore that an SMG could be reloaded from supplies of pistol ammunition! Similarly, some role-playing games simplify the available weapons to types: handgun, derringer, SMG, shotgun, assault rifle, sniper and so on.

Suppose, as a thought experiment, we are rationalizing the arsenal of arms. This may be for a space colony, a hypothetical nation or some other “blank-sheet”.

First, let us consider handguns and their ammunition. Bear in mind this ammunition will also be used in machine-pistols, sub-machine guns and pistol-calibre carbines. A friend of mine points out that one single round cannot fill all the applications these weapons might be used for. In addition to a medium/large-bore round there will need to be small-bore for training, hunting small game, pest control and a number of other uses. Let us call one the “Unique Pistol Round (UPR)” and the other the “Unique Small-bore Round (USR)”.

For military applications, our larger pistol round will need to be hard-hitting but sub-sonic. The capability for suppressed fire bis a requirement. For other applications, a flat-shooting, high-velocity, high-penetration round may be desired. In short, our round must be able to behave as either a .45 ACP or a .357 magnum. The only way I can see this realistically being achieved is for a single-calibre round available in a choice of bullet weights and loadings. A heavy, sub-sonic round for special operations, a heavy, high-velocity round for more general close combat, and lighter, higher-velocity rounds for applications that may want them. This round will probably have to be a medium-calibre (9-11mm) and it is desirable that it can use bullets of 200gr or heavier. In testing the .38 200gr load was the only medium-calibre of similar performance to larger-calibre handguns. Part of its terminal effectiveness may be due to .38/.357/9mm rounds of 200gr or higher weight having a greater tendency to tumble because of their length. The .45 ACP and other large-calibre rounds show us that sub-sonic heavy rounds can be effective, but given the smaller calibre and lower maximum weight it would be nice to have the option of a supersonic, 200gr+ loading. The 10mm Auto round meets these requirements, but we also want a round that permits a relativity compact weapon with a generous magazine capacity without making the grip too wide for smaller hands. The .40 S&W, on the other hand, needs a wider velocity range with 200gr+ loads. Similarly, most loadings of the .41 AE are in the sub-sonic range with heavier loads. A 200gr .357 magnum round might serve, if it was an automatic round, and compatible with grip size. Unfortunately most automatic rounds that have emulated the .357 have tried to reproduce the performance of its fast 125gr loads.

See this page for a further discussion of heavy, medium-calibre bullets.

So we need a narrow, short, low-bulk round that can also accommodate 200gr+ bullets or high-velocity loadings. The answer may lie with smaller, more powerful powder loads.

A 210gr at 1,150 fps or a 215gr at 970 fps was possible with the .41 AE. Similar performance is found with .41 Special loadings of 200-220gr. The UPR may need to be a shade larger in calibre than the 10mm.

Assuming we have a round that meets the above requirements, what weapons should we have? The core handgun should be an automatic pistol of about 7"/ 180mm overall length. As a primary weapon for concealed carry, you want a weapon of small bulk. As a secondary weapon for overt carry, a weapon of low weight is desirable, since you probably have enough other things to carry. Hence the standard gun is of compact/sub-compact size. For uniformed police officers and others who might need a pistol as an overtly-carried primary weapon there will be a variant of around 8.5"/ 215mm. For hunters and specialist sporting shooters the latter can be fitted with longer barrels.

Those of you that have read some of my other stuff will know I regard a hammerless, small-frame revolver as very suitable as a “pocket gun”. Such a weapon could use the same medium UPR round as the automatic pistols suggested above. The weapon would use lightweight materials, such a polymers and aluminium, and the polygonal cylinders used in the Chiappa Rhino revolvers are worth consideration. Whether the weapon would be five or six-shot would depend upon the bulk of the cylinder. Modern metallurgy has allowed seven and eight-shot medium-frame revolvers, so a really low-profile six-shot weapon may be practical.

Applications such as revolvers and derringers suggest that our hypothetical medium pistol round might be semi-rimmed, if it was a conventional, cased round.

There is a school of thought that revolvers are a better choice for users “not familiar with firearms”. For many modern automatics the only complicated concept is understanding what the slide is for, and this can easily be explained during mandatory firearms safety training. If you cannot understand what the slide does, you probably should not be around firearms, nor sharp objects in general. The presence of the pocket revolver in our theoretical arsenal offers the potential of a larger variant for home-defence and other non-combat roles. This would be the pocket model fitted with a more substantial grip and a longer barrel. Being derived from the pocket model, it will have an internal hammer, simplifying operation. There is a precedent for such an idea. The Colt Viper was a longer-barrelled, larger-gripped version of the Colt Cobra. Many modern revolvers are offered in 4" and 6" configurations. British medium-calibre military revolvers favoured 5" barrels, and taking this route may allow a single model of the larger revolver variant. If this is not practical, the standard model would probably be a 4", although some figure between 4" and 5" is possible.

Earlier I noted that a “small-bore” pistol round would also be needed. Such a round would also serve in rifles intended for small game or pest-control. I have designated this pistol and rifle round the Unique Small-bore Round, or USR. The USR will need to be available in a range of loadings. There will be a light, sub-sonic round for short-range practice, plinking and urban pest control. There will be a heavier sub-sonic loading for more serious uses. There will also need to be a higher-velocity loading for longer-range hunting of larger game and varmints. The USR would probably be based on the 5mm Craig, itself a centrefire version of the 5mm Remington Rimfire Magnum (5mm RFM). The 5mm RFM/Craig had a higher-velocity than the larger, longer .22 WMRF, more energy and a flatter trajectory. If a conventional round, the USR would be centrefire. Perhaps it should be semi-rimmed rather than rimmed. The case will need to accommodate heavier (60gr) bullets for sub-sonic shooting, so may need to be a little longer, but the round should still be compatible with pistol magazines.

Like the 10mm Auto, on paper the 5mm Craig has much to recommend it for its roles, but ironically neither was particularly successful. Market forces sometimes cannot be explained by logic.

Shotguns only warrant a short mention, since effectively there is already a single chambering in use. Most shotgunning roles are performed by the 12 gauge. Magnum loads rival the 10-bore and lighter loads can substitute for the 20-bore and lesser gauges. Arguably the only other shotgun chambering that might be needed is the .410. Possibly a shot-round based on the UPR could serve in this role.

This brings us to the field of rifles, or more accurately, rifles that do not use the USR. If we consider all of the roles rifle rounds may be used for it seems likely that a single cartridge will not serve then all, even before we figure in applications such as machine-guns.

If you have read some of my other works it will be not great surprise I suggest a 6.5mm (aka “6.6”) round as the general purpose rifle (GPR) round. The 6.5mm Creedmoor/.260 Rem gives us real-world, off the shelf examples. Long-range performance of these loads in sniper rifles is excellent, performance in GPMGs is likely to be similar. Interestingly the 6.5mm Creedmoor round still performs well from 16" barrels, suggesting the possibility of use in compact automatic rifles for closer-ranged combat.

The GPR meets the requirements for a full-power rifle round, but what about intermediate rounds? Let us define “intermediate round” in terms of function rather than form. The intermediate round is optimized for combat shooting at 500 metres or less. Recoil must allow accurate semi-automatic rapid fire, and accurate automatic fire at less than 50m.

In my article on the 6.6mm GPR I suggest 140gr as the standard loading, and an “urban” load of 100-120gr. Further reflection suggests that this lighter load might be created to have all the traits desirable in an intermediate round. The cartridge case may be a shade longer than that of a dedicated intermediate round, but this is offset by the versatility of being able to change capability simply by changing magazine.

Using a heavier (155gr+) bullet a sub-sonic GPR for special applications can be created.

The GPR is also suited for a large range of non-military applications. It has a light recoil yet is flat-shooting with considerable terminal energy and penetration. With a wide variety of bullet weights it is suited for game from caribou and black bear to foxes.

The versatility of the GPR suggests there will be a range of weapons designed to fire it. The standard assault rifle may need to be used in cramped conditions, so will have a 16" barrel if of conventional configuration. There will be at least two variants of the 16" weapon. One variant will be optimized for use with an underbarrel grenade launcher or DGL munitions. The other would be a support model with a heavier 16" barrel, heat sink and bipod. The grenadier and support variants are likely to be predominant in infantry forces, the standard model more common in non-infantry. The support version will be supplemented by a longer-barrelled GPMG, which serves in both the LMG and sustained fire roles. A longer-barrelled rifle based on the assault rifle would be suited for marksmen and snipers. In addition to this there would be a light, manual-action sniper rifle, similar to the L42A1/Enfield Enforcer. A lighter version of the manual-action rifle would be available for hunters, game wardens and others that do not want a semi-automatic.

The 6.5mm Creedmoor has established itself as a potent long-range and sniping round, giving a performance similar to the .300 Win Mag with considerably less recoil. Despite this, there is room in our arsenal for a larger-calibre sniping round, using a heavier bullet and better suited to anti-material roles. Perhaps I should call this the medium rifle round (MRR). The .338 Lapua Magnum is well established in this niche, offering excellent long-range performance without the weight penalty of .50 BMG weapons. The potential of the .338 would be increased even more if an APHEI round was available. The .338 LM is also suited to hunting large game. If the MRR is not the .338 LM, it should be something resembling it, of around .338-.375 calibre, such as the 9.5 x70mm ELR/Tornado.

On the topic of large animals, a friend of mine hunted moose with a supersonic loading of the .510 Whisper. This round is based on the .338 Lapua Magnum/.416 Rigby cartridge case. The .50 Whisper is a similar round based on the .460 Weatherby Magnum case. Another round by SSK based on the .460 Weatherby Magnum case is the .50 Peacekeeper. This fires 650 to 750 gr bullets with muzzle velocities that range from 2,200 to 2,400 ft/s. The .50 Peacekeeper is claimed to have 88% of the performance of a .50 BMG rifle while offering less recoil in a 12-15lb rifle than a .50 BMG in a 30-35lb weapon. If we have the .338 LM in our family of rounds, then a .510 Whisper with Peacekeeper-type performance might be useful as the large rifle round (LRR). Even in sub-sonic loadings, the .510 Whisper gives sub-MOA accuracy at 600m. There are obvious logistical advantages to a large calibre-rifle round that can use bullets developed for heavy machine-guns. For example, APHEI anti-material rounds in .50 are already available. The .510/LLR would also have applications for control of dangerous large animals. The LRR compliments the MRR, offering a harder punch at shorter ranges or for suppressed shooting.

So far we have the 5mm USR, 10mm UPR, 6.6mm GPR, .338 LM/MRR and .510/LRR, to which we can add the .50 BMG for HMG, AMR and heavy sniper use.

Of course, this selection will not please everybody. Within this group there is still potential for some interesting “wildcats” or “crossbreeds”. It can be argued the .510 is the equivalent of a wildcat of the .338 LM and .50 BMG.

By the Author of the Scrapboard :

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