It is you, the gun, or the ammo.
The biggest factor here is , 'Yew'.
I want to see the man who can shoot up to a milspec Factory Colt Sporter Rifle with Red Box Federal 62 grain FMJs or using the U.S. M885 round. Go ahead, shoot the timed standing to sitting and prone positions from 200, 300 and 600 meters.
The present day Palma Team shooters and Individual record breakers look at me eye-to-eye and tell me to reload .223 or .308 on you starndard everyday press and spend you time & money on...can you believe this...practice.
What do they know?