I honestly don't believe the 6.8mm NGSW will ever show up. They're asking for the insane from that piece of technology.
Guns N Ammo laid out the issues:
https://www.gunsandammo.com/editoria...ntinues/372371
Quote:
While the details about the Army’s projectile are still classified, here is my best guess on its potential makeup. First off, I bet it weighs approximately 135 to 140 grains and must travel at velocities close to 3,100 feet per second (fps) from 13- to 16-inch barrels to meet Army needs. The only way to get that kind of performance from those lengths of barrel is to run chamber pressures up around 80,000 to 90,000 pounds per square inch (psi). This would put proof loads over 100,000 psi. That’s a spicy meatball!
High-pressure ammunition is a hotly contested topic, and I’ve been very critical of the concept. I remain critical of anything that raises chamber pressures above 55,000 psi in a direct-*impingement firearm. Anything higher than that and the gun quickly beats itself to death.
Pressures exceeding 55,000 psi in rifles designed for high pressure come with some definite advantages and a handful of disadvantages. The biggest advantages of high-pressure ammunition are substantially increased velocities, the option to attain those velocities from much shorter barrels and improved terminal effects.
All-brass cases can’t handle that kind of pressure and can result in ruptured/split cases, primers being blown out of their pockets, or case heads separating from the body. Either way, all that pressure will go somewhere it isn’t wanted.
|
Basically:
SIG SAUER:.277 SIG Fury at SHOT 2020. SIG’s military designation for their cartridge is 6.8x51mm. This round uses a three-piece case that has a steel case head, brass body and a locking washer that mechanically connects the two.
True Velocity/General Dynamics: A polymer cased ammo.
Textron & Winchester: Plastic telescoped cased ammo.
--------------
All this is because CoS Mark Milley has a hard on for defeating Level IV body armor at 600~ meters in an individual weapon
My opinion?
Nobody ever pointed out to Mark Milley that at 600~ meters, you can just use regular 5.56mm ammo to keep the enemy suppressed while you bring marksmen fire (all that extra money spent over the last few years on ACOGs and variable scopes etc) to shoot them in the head.