New Marine Corps weapon to replace SAW

[dobrodan]

Would a pistol still be nothing more than a backup weapon if you were sending 62gr projectiles down range at 2000+ fps instead of a big slow slug?

Yes it would. A pistol is something you use to fight your way back to your rifle.

A PDW/SMG would be something else, as that would be a lot more controllable and accurate.

I have found myself avoiding to wear a pistol in the field (unless carrying a MG, sniper-rifle or CG84mm), as it typically only brings extra weight and cumbersomeness without really adding to my capabilities. I would much rather bring a mag or two extra for my rifle.

I like pistols, but IMO, they are of limited relevance for infantry in the field. The best backup-weapon is the one in the hands of your buddy right next to you.