New Cartridge Developments and Implications for Dismounted Infantry Soldiers

[JASmith]

So we still need eco-friendly?

I agree, its tougher to do, but its still doable. In fact, a solid copper bullet would work. 180 grain Barnes with a BC or .473 can be loaded easily to 2700 FPS with easily available powders. Using the newer Superperformance powders, I'd bet you could get over 2800 out of them, at standard length.

Bumping to 200 grains loses several hundred feet per second, but is doable, with 2600 FPS velocities at standard length.

I've looked at the loaded ammunition offered for the TTSX and compared with that for the 168 gr. Game King:

Barnes 168 gr TTSX Muzzle Velocity: 2680 fps
Federal 165 gr TSX Muzzle Velocity: 2700 fps
Federal 165 Sierra Game King Muzzle Velocity: 2700 fps

I've also looked at the load recommendations by Barnes and found that they suggest using the same data for TTSX as used for TSX and MRX bullets. The velocities are consistent with the commercial ammunition.

Chances are that the perfomance boost available with the newest powders will perform in line with the 100-150 ft/sec claimed by Hodgdon. Hornady offers a Superformance load for the 168gr GMX bullet with a muzzle Velocity of 2750 fps. It is true that steel is slightly less dense than copper and the powders may not deliver all that is promised, the difference isn't enough to make Bill's velocity estimates change by a significant amount.

In any event, we know that we can get 2750 with a 168 gr TTSX. Removing the plastic nose plug and replacing with an appropriate length hardened steel penetrator won't lengthen the bullet by an appreciable amount, particularly if the meplat is the same size as that of the TSX.

Hence, I would tend to go with Bill's estimates as the optimistic upper bound and with the demonstrated 2750 for the 168 gr as the lower bound.

I also found loads in a respected reloading site (Ammoguide.com) listing velocities in excess of 2700 ft/sec for the XLC coated bullet.