Been loading since ‘66 and I “grew up” just going at it with powder charge. I did experiment with my 243 varmint loads but my seating depth changes were rudimentary at best. I got more serious about it with a Hornady tool
My most accurate “carry around” rifle is probably a 221 FB, Model 700. I’ve related this before but on one occasion it put 10, 40 gr Berger HP into 0.505” at 100 yds. I figured that if I wanted to really investigate the two techniques that it would be the rifle to use. So I went at both ways, first changing powder charges and a recommended seating depth and then tinkering with seating depth both ways. Then I went the other way starting just barely off the lands with a middle of the road powder charge and then moving the seating depth. I could generally see a pattern in group tightening or loosening. Then to changing powder charges.
Not necessarily the perfect study design with me doing all the shooting but with both techniques, I ended up at the same point...the same powder and seating depth.
So now I still start with powder charge tests and if I get the velocities and reasonable accuracy I want, I’ll then go to seating depth. If get really low velocities or huge groups I'll go at it with another bullet first or second, with another powder. Someone once said, “good groups MAY repeat but bad groups will ALWAYS repeat.” 😊
Last edited by navlav8r; 09/16/20.
