Stumbled onto your link and am glad that I did so....also took advice of Clint Smith to shoot ten shots to look at dispersion--no more three shot groups that cannot be reproduced day-in, day-out. I feel like I learned a lot...
Started with a Kimber that was shooting so poorly that I was tempted to pound it in the ground for use as a fence post! This Kimber in .308 was rebarreled (for cheap) and still couldn't get it to shoot as consistently as I would have liked. Well enough but not great. Performed the magazine mod, got a FAT wrench, did an Acraglass bedding job (looks like crap), and torqued the action down to 65in/lbs. Had to take it apart and squeeze the mag lips together as the bullets would pop up through the mag when three or more cartridges were loaded.
I'm shooting 168gr Berger Classic Hunters, 43.0gr IMR 8208 XBR. COAL: 2.834", CBTO is determined (for me) by placing a loaded cartridge into my redding die and measuring cartridge base to top of the die: 4.075". My 100-yard, twenty shot dispersion was 2.3" laterally and 1.2" vertically. After forty-five minutes of cool down my next five shot group was 0.47" lateral dispersion and 0.37" vertical dispersion. Four shots in same hole and after verifying that there were really four shots in same hole I lost my concentration a tiny bit maybe...could NOT believe what I was doing.
My observation is that after five shots the barrel was pretty darn hot! I believe that my group widened secondary to the heat mirage distorting the sights so much that I had trouble centering the sights in a repeatable fashion. I am heading out today to shoot another five shots at the last target to see if the sum stays tight or opens up. Another possible confounding factor is that I was shooting a 338-378 Wby beforehand and the blast is enough that I start to flinch a bit after 4-5 shots... I think that my loading is consistent, my practice is pretty good, the bench setting was good and the weather was really good. The 10-shot, 200yard results were 3.0" lateral, 2.3" vertical. First four in same hole. The 10-shot, 300yard results were 4.1" lateral, 3.2" vertical. First four were sub 1" in both dimensions. Again, beyond anything that I have ever done before with any rifle. Thank you all again for a free lesson. Will try to remember to post again.
