Twice, I've been squadded with a new shooter having his first time on the 1000 yard line in a prone match. Both times I let him use my rifle and ammo. After a two minute lesson on how to hold the rifle in prone, squeeze the trigger so the scope's crosshairs wiggle inside the X ring and don't jump out of it when he dry fires the rifle, they've shot scores in the mid to high 190's out of 200. They did what they learned how to do. One of 'em secretly got a couple of Sierra 190's and a fired .30-.338 case from my wife and made a fancy belt buckle with them which he gave me as a "thanks for the help" gift at the next match.
Both had no pre-concieved notions about how to shoot accurate. Same as most of the Plebes (freshmen) at the US Naval Academy when the USN Rifle Team trained them one summer in rifle shooting and marksmanship. Ignorance is bliss in the shooting sports; those smart but ignorant will grasp the correct concepts and techniques much, much faster than the n'er-do-well know-it-all's that permeate the shooting sports.
US Navy Distinguished Marksman Badge 153
Former USA Palma Team Member
NRA High Power Long Range High Master
NRA Smallbore Prone Master