1: Placement
2: Projectile selection
3: Cartridge headstamp
That's the order of importance,in stopping heartbeats.
Myself,I don't think head shooting Freezer Meat mandates a 20mm MK12,stoked with MK106 Mod O (HEI).
Nor can I see myself in a tissy,over what someone else finds fortune in.
Gimme a 7-08 and an X and the rest is easy......................