Optimized Caliber

[JASmith]

... - but they found that it was the M249 which was being left behind in favour of a MK48 and M240 combination....

You may say that this is all in the mind but I doubt that, on the basis of some of the first-hand reports I've heard. Even if it is, I wouldn't dismiss too quickly a factor which has such a powerful effect on combat morale.

Would the decisions be the same if one or both of the MK48 and M240 were chambered for the Grendel?

It is said that morale is a weapon in its own right. The last thing one wants is a soldier who feels his weapon is useless. At the extremes, that can happen with ineffective ammo or heavy ammo that doesn't allow enough rounds to be carried. It is probably why we don't see many .50 BMGs used in this role.

One thing is true -- the Grendel round is lighter than the 7.62 NATO. Also, as you know, many of us argue that the other side either won't see the difference in effectiveness or the improved ability to hit with the Grendel will make him less comfortable. That would be a good thing...