Ft Collins, CO –-(Ammoland.com)- “First, they tell you it will never work, and they can prove it! Then, they admit it does work, but insist it’s not important. Finally, they concede it is important, but assure you they’ve know about it for years!” ~ Kettering
Military Rifle Calibers:
During the black-powder era of the 18th and 19th Centuries, bullet diameters on military rifle cartridges ranged from 11mm to 19mm (45 to 75 caliber).
The terminal effect was surely “adequate,” but range and accuracy were very limited, particularly with smooth-bore muskets.
As we entered the breech-loading era and the second half of the 19th Century, bullet diameters were generally reduced. Rifled bores became the norm.
However, most bullets were still blunt, and because of black powder’s pressure curve, bullet velocities did not exceed the speed of sound by much.
With the advent of metallic cartridges, rims were used for the sake of obturation, consistent headspacing, and easy case extraction, particularly with the coming of spring-loaded, under-barrel, tube magazines, and center-fire cartridges.
With the invention of “smokeless” propellant in the 1880s, velocities were greatly increased, along with useable ranges (so-called because “smokeless” propellant residue is almost all gaseous, and the gas is mostly transparent; by contrast, black-powder residue is substantial and mostly particulate, hence the characteristic dense, white cloud and excessive fouling)
Aerodynamic “spitzer” bullets, reduced bullet diameter, and increased bullet length all became necessary, so as to step-up “ballistic coefficient” sufficiently to take full advantage of supersonic velocities that were now possible.
Sights became more precise and more precisely adjustable.
But, spitzer bullets simultaneously made tube-magazines obsolete, as the pointed bullet put pressure on the primer of the cartridge in front of it.
Spring-loaded, box magazines were the obvious solution, but that made the rim on rimmed cartridges a problem. One rim could block forward movement of the cartridge above it, thus retarding the feeding process.
The phenomenon was called “rim-lock,” and it quickly ushered-in the era of necked cartridges!
With necked cartridges, rims are gone, replaced with flush “extractor rings,” and the cartridge now headspaced on its shoulder, so smooth, uninterrupted feeding from double-column, box magazines (soon to become detachable) was now possible.
Rimmed cartridges, like the 30-40 Krag, 303 British, 8mm French Lebel, Soviet 7.62x54R all gradually became obsolete, although the 303 British hung-on through the end of WWII, and the 7.62x54R is still with us!
Through the first half of the Twentieth Century, military rifle cartridges were all between 6.5mm and 8mm (25-31 caliber), in order to achieve an acceptable rifle/ammunition compromise that balances:
- Adequate range
- Adequate penetration
- Manageable recoil
- Barrel length
- Barrel life
- Magazine capacity, and
- Terminal effect
Those twelve issues represent competing, unavoidable trade-offs confronting weapon and ammunition designers. It is not possible to “adjust” any one of those without affecting all the rest. Go too far in any one direction, and you immediately run into deal-busting troubles!
Now that nations have equipped their armed forces for self-loading rifles, overheating, barrel life, weight, bulk, and durability have all become particularly thorny subjects!
In the first half of the Twentieth Century, horse-mounted cavalry units persisted, although they were mostly obsolete by the end of WWI.
However, with cavalry still a military consideration, “adequate terminal effect” implied an ability to take-down a horse with one shot!
In our modern era, with horses no longer a consideration, 5.5mm (22 caliber) bullets (5.56×45 NATO, 5.45×39 Soviet, 5.7×28 FN) have emerged and are considered (by some) appropriate chamberings for modern, military main-battle rifles, but there is far from “universal agreement” on that!
Inadequate penetration and inadequate range have been persistently (since the 1960s) cited as critical failings with this modern generation small-caliber military cartridges.
Interminable technological attempts to address these two issues have failed to silence critics, including me.
“‘Three Confusions’ that tirelessly haunt Western Civilization:
The first confuses feasibility with legitimacy:
‘When it can be done, it ought to be done!’
The second confuses feasibility with reality:
‘When it is supposed to work, it works!’
The third presupposes that technology, without fail, represents the ultimate good:
‘When it’s technologically superior, it’s absolutely superior!’” ~ Anon
About John Farnam & Defense Training International, Inc
As a defensive weapons and tactics instructor John Farnam will urge you, based on your own beliefs, to make up your mind in advance as to what you would do when faced with an imminent lethal threat. You should, of course, also decide what preparations you should make in advance if any. Defense Training International wants to make sure that their students fully understand the physical, legal, psychological, and societal consequences of their actions or in-actions.
It is our duty to make you aware of certain unpleasant physical realities intrinsic to the Planet Earth. Mr. Farnam is happy to be your counselor and advisor. Visit: www.defense-training.com