Help me choose a load for .260 Remington

[Doomslayer]

Hi,

I have been lurking for a long time here on the Hide. Here goes: I have a .260 Rem and I have been using Lapua Scenar 139gr with great success out to about 1070meters. However I am having difficulty getting these bullets reliably as I am not based in the USA.

I decided to develop loads on Sierra Matchking 142gr and Berger VLD target 140gr as alternatives.

All groups were shot from bench at 100m, with Caldwell lead sled.

Rifle info: Broughton 1 in 10 twist 26" long, Remington 700 action, AICS with viper skins, Jewel trigger, Schmidt Bender 4-16 x 52 PMII.

Cartridge info: lapua brass, CCI200 primers, S365 powder (locally made powder here in South Africa as USA stuff unobtanium here). Jump 0.5mm

The problem I have is that the groups are very close to each other in terms of size - so do I just pick one, or should I reshoot groups at greater distance, say 200 or 300m?

First set of images are for SMK 142gr with 40.4gr, 40.7gr, 41.0gr and 41.3gr S365 powder. Velociies is in the 2720-40 fps range. The 40.7 load gave me the least variation in velocity - 5fps over 5 rounds.

 

[Doomslayer]

and for the Bergers VLD Target 140gr

 

[seanhagerty]

142snk's w. 40.7 gr's based on where the groups are on the target. I would go back and shoot3 shot grouos of 40.6, 40.7, 40.8, 40.9, 41.0, 41.1 to see where they pattern. Shoot the at 100yds at the same oal and shoot them round robin at 6 different targets allowing the barrel too cool off between shots.

Look up ocw for this process.

Sean