Cold bore zero versus (very) Hot bore zero “test”

[donrleonard]

Go test it. Shoot a 10 round string and number every shot. Let your barrel cool between each shot. Then repeat it without cooling. It’ll give you a pretty good idea of how, if at all, barrel heat is affecting your group.

FWIW I’ve had two lightweight rifles with pencil barrels that will rattle out a 10 round group with no ill effects. One is a 6.5 and the other was a .280 Remington.

Great idea. Challenge accepted!

 

[wind gypsy]

It's a great point, and one that I need to drill on for hunting--staying in the scope, spotting impacts, and being prepared to take follow-up shots.

The thing that puzzles me is just how consistent it is. Two tight shots low, two high, and a random 5th shot inside of a 2" cone.

Do they progress in the same direction?

Other shooting gurus, like Joseph von Benedikt and Cliff Gray, do commonly see accuracy open up after as few as two or as many as 5-7 shots. Given their vast experience, I can't help but wonder if there isn't some systematic variance in the 1-10 shot range inside these 30-shot strings that Form reported here.

Not familiar with the Cliff Gray fella. I’m guessing they get a bunch of production guns that wear barrels that are not adequately stress relieved, carbon barrels that walk, etc so I’m sure it happens to a degree and I’m sure sometimes it’s not heat that is causing the issue as well but that’s what everyone is conditioned to assume.