What do you think of the US Army going to the Sig XM5 6.8x51?

[TomAiello]

For a rifle you have to carry around, the M4 in 6mm ARC has a lot of advantages.

[Scandi Grind]

The Sig MCX platform is already capable of changing calibers easily, so it could be smart of them to have a smaller round for other applications. The problem with the MCX Spear though, is that it is heavier than it needs to be for a smaller round.

For me personally weight isn't usually the biggest factor though. That is why I have a Tavor.

[Doc Dan]

I think the 6mm ARC is a brilliant round and the SF helped to develop it for their needs. If it serves their needs, why not other units as well? It probably will not penetrate body armor at 1000 meters, but it will penetrate a helmet.