Ultratech Intermediate Rounds?

[Anthony]

Originally Posted by weby

But even halving that 0.038 produces too low result as a caseless version would still likely fire the 180 grain bullet alone is thus about 0.026lb and then you add the propellant.

Checking numbers, halving seems about right for necked center-fire rifle cartridges. It doesn't work for stuff with a lower ratio of propellant to bullet, since that means you can have a smaller case and/or thinner case walls.

[sir_pudding]

Originally Posted by Anthony

The constraints for a sniper rifle are significantly different from the constraints for an assault rifle, somewhat more finicky ammunition is tolerable, though on the reverse side of that ammo weight is also less of a constraint. Still, I'd bet on the next step being saboted ammunition, not caseless.

I'm saying that there's very likely to be versions of these rifles (or as you say, to the M16 or M4) without any change to the cartridge at all. The XM500 is mostly about making a bullpup AM rifle.

[Anthony]

Originally Posted by Fred Brackin

It could be even worse than that. The "next rifle" with novel ammo may not happen until someone makes a reliable SAW that gets a lot of benefit from lighter ammo. Once you have that "killer app" SAW then you get the rifle too for ammo compatibility.

Of course, that could be the LSAT LMG.