The Firing Line Forums - View Single Post - Army's new 6.8 cartridge with development information:

Bartholomew Roberts · December 30, 2018, 07:39 AM

The new 6.8 round has been designated XM1186. I’m not sure what the 6.5 version was designated.

Based on other reporting, both bullets are based on the “Enhanced Performance Round” (EPR) that is used in M855A1 and M80A1.

In some articles, Gen. Milley has discussed defeating body armor out to 600m as a requirement. In others, Gen. Milley has discussed defeating “any currently known body armor” without specifying a range. If the intention is to defeat any currently known body armor at 600m, then, in my view, the 2,800fps in RC20’s link ain’t gonna get ‘er done with a 120-130gr EPR style bullet. You’d need tungsten or a different construction that isn’t practical for general purpose construction.

As far as soft-tissue performance, any round that can penetrate any known body armor at 600m will have zero problem with soft tissue performance because it will be packing a lot of energy (around 3,400 ft/lbs I’d guess). So it looks like the low-recoil leg of the triangle is either out the window or subject to some impressive advances in technical knowledge,

All of this in a weapon less than 15lbs and 35” long with optic and suppresssor according to RC20’s link. Also a 60rpm sustained rate of fire and a less than 10% accuracy loss after 10,000 rounds based on the NGSAR requirements.

December 30, 2018, 07:39 AM	#42
Bartholomew Roberts member Join Date: June 12, 2000 Location: Texas and Oklahoma area Posts: 8,462	The new 6.8 round has been designated XM1186. I’m not sure what the 6.5 version was designated. Based on other reporting, both bullets are based on the “Enhanced Performance Round” (EPR) that is used in M855A1 and M80A1. In some articles, Gen. Milley has discussed defeating body armor out to 600m as a requirement. In others, Gen. Milley has discussed defeating “any currently known body armor” without specifying a range. If the intention is to defeat any currently known body armor at 600m, then, in my view, the 2,800fps in RC20’s link ain’t gonna get ‘er done with a 120-130gr EPR style bullet. You’d need tungsten or a different construction that isn’t practical for general purpose construction. As far as soft-tissue performance, any round that can penetrate any known body armor at 600m will have zero problem with soft tissue performance because it will be packing a lot of energy (around 3,400 ft/lbs I’d guess). So it looks like the low-recoil leg of the triangle is either out the window or subject to some impressive advances in technical knowledge, All of this in a weapon less than 15lbs and 35” long with optic and suppresssor according to RC20’s link. Also a 60rpm sustained rate of fire and a less than 10% accuracy loss after 10,000 rounds based on the NGSAR requirements.