They should make a book on shooting positions for old Farts…
The military doesn’t have as many old farts and God knows we use all kinds of crutches in competition..
Aside from that - knowing what impacts where a rifle shoots is wildly absent information amongst shooters who think they know what they are doing. At least is was for me as I came up through the shooting ranks (learned from a bunch of old fart shooters that knew a great deal more than me).
Shoot PRS, High power, and Benchrest and each group will teach you a ton of stuff… If you find some old farts that know what they are doing, and relatively can keep your mouth shut long enough you’ll learn stuff.
Heck I’ve learned some critical things from Guys like Saddlesore - but he used to be a NRA cert. trainer - so you never know…
