Quote Originally Posted by kennyc View Post
nope otherwise factory ammo wouldn't hit squat! get your powder charge sorted out and then if you must play with the length to get the minimum group dispersion, too many people spend too much time fretting about the jump to the lands before getting the rifle shooting well.
I have to say I've found the complete opposite. COL has made all the difference, powder change just makes the group go in different places (within reason). Sure if you have the wrong COL then powder changes might result in a nice group, but not consistently.

Just my 2p

And if its raining then this and part 2 is worth watching. But skip the bits about concentricity and come back when you have 1/2 moa groups.