What should our standard military cartridge be?

[Spartan]

Personally I see nothing wring with 7.62 x51 (308) you could experiment with bullets ... but stopping power and range are there.... 5.56 is fine ... but you need head shots and multiple rounds .... why not go with 308 and do it with one rounds .., same with 45acp over 9mm ... 9mm is fine but you need either the right shot or multiple....

the 270 .... it don't save much weight .... great deer round but

[Grayskies]

How does the .270 compare with the .308 for energy at target?

[DanM]

Link to an article entitled "Assault Rifles And Their Ammunition: History And Prospects".

http://quarryhs.co.uk/Assault.htm

It defines the subject and then discusses the history and development of the worlds intermediate power rifle and its cartridge. If you read carefully you will even find that the M-16 was adopted as a stop-gap tool on the way to an even more unusual weapon.

But to the OP's question: the standard military cartridge depends on what the military defines by its requirement(s).

Example; The M14 was supposed to replace the M-1 Garand rifle, the M-1 Carbine, and the Browning Automatic Rifle. It failed in that role because it made too many compromises. It was too light for accurate full-auto fire, but too heavy as a replacement for the M-1 Carbine.

Example; In 1957 the Commander of the U. S. Continental Army Command (CONARC) requested that the new army select-fire rifle's (Project SALVO) bullet had to penetrate a standard U.S. steel helmet, body armor, or a steel plate of 0.135 inches (3.4 mm) and retain a velocity in excess of the speed of sound at 500 yards (460 m), while equaling or exceeding the "wounding" ability of the .30 Carbine. This amounted to about a third of the energy of a .30-06 round.

From the linked article;

The August 2011 report by the US Army's PEO Soldier report titled Soldier Battlefield Effectiveness includes a number of points in favour of general-purpose weapons and ammunition, summarised concisely in this:

"Ultimately, Army service rifles must be general purpose in nature and embody a series of tradeoffs that balance optimum performance for a wide range of possible missions in a range of operating environments. With global missions taking Soldiers from islands to mountains and jungles to deserts, the Army can’t buy 1.1 million new service rifles every time it’s called upon to operate in a different environment."

So it comes down to this; what is the requirement?