I'm beginning to play with bullet jump in my .308. Shooting 175 SMK, I've dialed the powder charge down to the most accurate load at 42.5gr Varget. Only wanting to deal with one variable at a time, all loads were set at .008" off the lands.
I've just loaded some at -.005", and I'm not sure what to load next. -010'? -.020". How much of an increment do I want between the loads to see a difference? I'm currently low on these bullets and don't want to waste any, nor do I want to buy more if they won't shoot well. The current load of 42.5 Varget, 175 SMK, and -.008" off the lands, yields a .440" group @ 100yds.
The next question is how much of a pressure change will I get by setting the bullet back -.010 or -.020, etc? I'm not at max charge, no pressure signs. But I'm getting 2890fps, with is inexplicable (maybe my chrono is off)
My ultimate goal is to develop a 1000yd load. My 168's shoot very well at 500yds. (sub MOA), but I'm reading that they won't do well at 1000yds.
FWIW, the rifle is a DSG 11VT with Vortex Viper PST. Chamber measurement CBTO is 2.218 with this bullet. OAL comes to 2.275 @ -.008". (not that OAL is important)
Thanks for any advice.