Peter. Can you post some more details on the load that gave you such good results? Thanks JCS
JCS
Yes , as follows, and this was done in 2 separate stages.
FWIW, I have settled on a load right out of the Nosler #6 Book for the .260
40 Gns RL15, Nosler Custom Brass, Fed GM210M primer, 120 Gn NBT. Gives me .3 MOA out of a Tikka 595 action, LW 22" 1:9 twist barrel. Velocity is 2895 fps with extreme spread 7 fps on a 5 round group.
But ....
For interest, I started the load development at .020" off the lands using 37 - 40 Gns RL 15 in .5 Gn increments; and they grouped kind of OK, all under 1" at 100, with the best group at just under .5 on the 40Gn load, which I was inclined to settle for as the loads tested were all very low spread in velocity. But thought that I ought to experiment with seating depth as well, and so next trip to the range I shot 3 at .025; 3 at .030; 3 at .035; and 3 at .040 which was where the group ( or me) started to open up again. The best group of all was at .035 which gave the .3MOA grouping, so I settled on that and I haven't done anything else since. The seating depth experiments consisted of 12 shots, with 9 fps extreme spread, 9 of them under 6fps difference.
OK , the Chrono probably isn't that accurate, in fact I doubt it.... but it is the best results that I have managed in nearly 20 years of reloading in my fairly amateurish way, so I was fairly pleased to be able to replicate the Nosler load pretty much exactly.
I had used Lapua .243 brass, necked up to .260 and neck turned by Callum, I used that to shoot 100 Gn BTs and it always shot less than .5 MOA at about 3250 fps in a 26" barrel, but it has taken a leap
forward since I had the barrel shortened to 22", and is a much better handling stalking rifle. The consistency of the load, I am inclined to put down to the brass regularity and constant volume, maybe I am mistaken? Heck..... it works; and the deer hate it.
Best
Peter