Soldiers from 2nd Brigade Combat Team, 1st Infantry Division, pull security during an exercise at the National Training Center, Fort Irwin, California.

The folks who make the decisions about what guns our armed forced will carry into battle have been arguing back and forth about one point for about 100 years now: what is the optical caliber for small arms, specially the battle or assault rifle.

With the small and speedy 5.56mm reigning for more than 50 years, bolstered by larger, harder hitting .30 caliber ammo, it seems the U.S. Army may be moving toward something in between.

This story from Army Times says Army researchers are testing six ammunition variants in “intermediate calibers” which fall between the currently issued 7.62 NATO and 5.56×45 NATO to create a new light machine gun and inform the next generation of individual assault rifle/ammo combinations.

The story says the actual gun designs being tested aren’t anything on the current market and will be “unconventional,” whatever that means.

The story says some of the calibers being tested include the .260 Remington, 6.5 Creedmoor, .264 USA and other “non-commercial intermediate calibers, including cased telescoped ammo.”

Telescoping ammunition is made of a polymer case that fully encases the bullet, which is surrounded by propellant.

Eliminating the brass lets the telescoped ammo be about 40 percent lighter than traditional ammo, but the cartridges are fatter, resulting in smaller magazine capacities.

Army officials say the new gun could be in soldiers’ hands by 2020 and that the new rifle and round combination will give troops a weapon they can carry with about the same number of rounds as the current 5.56mm configurations, but with greater range and accuracy as well as little change in weight.

The story says the study devoted to a new round started in at least 2014 and is expected to conclude in the next three months, when portions of that report and its findings will likely be made public.

There have been a number of studies and reports regarding U.S. troops being overmatched on the battlefield against enemies firing more powerful assault rifles, especially at greater distances, where the 5.56mm round loses much of its lethality.

The semi-auto M1 Garand replaced the Springfield ’03 in 1937, but was also chambered for the .30-06 Springfield.

Even back when John Garand was designing his now-legendary M1 Garand rifle in the 1920s, he built both a .30 caliber and .276 caliber version, the story says. As the U.S. military was already set up for .30 caliber ammo, it went with that option.

The trend continued through the reworking of the M1, which became the M14 chambered in 7.62 NATO (.308 Win.).

After the beginning of the Vietnam War, U.S. forces switched to the M16 platform and the 5.56, and the argument as raged ever since with some claiming the 5.56 didn’t have the power necessary to penetrate cover and foliage.

The story says U.S. Special Operations Command is currently testing a new commercially available sniper rifle using the .260 Remington and 6.5 mm Creedmoor rounds, which “stay supersonic longer, have less wind drift and better terminal performance than 7.62mm ammunition,” said Maj. Aron Hauquitz.

SOCOM is also developing polymer ammunition in 6.5mm to reduce the weight load.

That’s important, because with an early third reduction in weight, the polymer 7.62 rounds could weight the same as brass-cased 5.56 rounds.

For the full story from Army Times, go here.

The polymer-cased rounds are wider than standard loads, but pack much more of a punch for its weight.

Army Considers New Rifle that Fires “Telescoped” Ammo