Just to let people know that all is not skittles and beer in the world of Kimber owners...
I just bought a M84 Montana in .260 Rem and loaded up a batch of handloads to start developing from. Ten different handloads were prepared in new Remington brass using 100gr partitions, 125gr partitions and Sierra 140gr SPBTs. Powders were IMR4350, IMR and H4831, RL19 and H1000. Seating depths were all close to 2.75-2.78. Scope was a known Leupold
VXIII 2.5-8 in properly installed Leupold
rings and Kimber bases. Shooting conditions were perfect--dead calm and 70-75 degrees. Groups of five shots each at 100 yards were fired over 20 minute intervals, and the barrel allowed to cool completely between groups. Velocities were high and in some cases exceptionally uniform (s.d. of less than 10fps), and pressures moderate to moderately high with neatly flattened but not cratered WLR primers. The barrel did not foul with any of the bullets.
Best group of the day was 2.5" for 5 shots, running up to 4", and a solid majority were over 3". My target looked like I had shot it with buckshot by the end of the day.
Wow. The trigger letoff is a heavenly 2lbs. The rifle is tightly seated to the bedding, the scope mount is correctly installed, and I know how to shoot. I've got four other rifles in the safe that routinely shoot 1/2 moa with my handloads. There is nothing obviously wrong with the crowning of the rifle or anything else, except that the bolt head sits rather loosely in the lockup and may not be engaging evenly. There is nothing systematic in the groups that I can see to suggest a cause--no linear stringing in any particular direction--and the barrel appears to be amply floated back to the breech swell.
I'm stumped. I'm sending the gun back to Kimber to see whether they can figure it out. Any ideas from the readership?