Best Do It All Varmint Cartridge

[A_Brandt]

In an AR-15?

Missed that part. AR-15 platform, 22 arc would get my vote if strictly talkin varmint rigs in the AR-15 platform. Although I have a 6mm Arc in the AR-15 to double for varmint and effective deer rig

 

[Okie-hunter]

My first choice in AR platform is 6arc. Then 22arc. I’m getting 3150fps with 70gr NBT out of my 18” 6arc. Big enough to comfortably shoot pigs, hammers coyotes, can shoot from 55gr to 108+ bullets.
ETA: the lower SD of 6mm bullets compared to .224 in similar bullet weights will also make for more rapid expansion. I like rapid expansion on varmints.