I just run slugs at all times on my Grinders. I'm not blowing 350 infantry resources to only be good out to 8meters and only be competitive with other MAXes out to 5meters. As long as you know how to work around the somewhat shoddy CoF on Grinders, you kill infantry at 20 meters easily and damage Maxes (because they're larger targets) beyond that. Scatters/Mattocks extend those ranges by around 10m with tighter cones of fire, but I prefer the Grinders' extra 2000 (4 slugs) damage before reloading for situations where enemy MAXes get up in my grill. Yeah it's ****** that our guns basically need exmags to do decent anti-max damage and slugs to be any good at mid range but whatcha gonna do? We're never gonna get Gauss Rifle arms. I love slug Grinders, and they're cheapest too. I really enjoy slug Scattercannons on my second NC character too but I'm not buying exmags for another pair of guns for either alt. So one stays Grinders, one Scatters. At least with slugs I can pretend the NC's gimmick still is 'lower rate of fire, higher damage per bullet' instead of SHOTGUNSSHOTGUNSSHOTGUNS
When not using Ravens, I use an extended mag/slug hacksaw on my left arm and an ext mag scat on my right as a back up. Works pretty well for me.
I hardly even play anymore, but I just said to hell with it and got the extended capacity on the grinders. I don't care too much for this game anymore, so I didn't have any qualms about dropping 2000 certs