Military round comparisons

[stanc]

LRRPF52 suggested three loadings- assault rifle, machinegun, and dm/sniper rifle. Another thread I read recently talked about 2 loadings, assault and machinegun, with the first being around 100gr. and the second 140gr. Obviously the sniper and assault loadings would have to have the same COAL due to being loaded in magazines, but what about the machinegun? Could (or should?) you load the heavier 140gr loads longer so as to allow more powder and thus have more velocity and power in a belt fed machinegun which does not have to worry about mag length? Or should they all fit in a magazine?

It depends upon whether you wish to discuss what could be done in theory, or what the military is likely to opt for in practice. Historically, a single loading has been used for mag-fed rifles and belt-fed machine guns. IMO, that is unlikely to change, so proposing different loads for the two types of weapons is destined to fail.