All very time consuming for sure. Yes, Targex (as it seems with projectiles from pretty much any other manufacturer) would no doubt be faster for reaching a decision on suitability. I only shoot 7mm and 25-cal though.
Puku, with these two jumps the longer 0.080" gave better groups than 0.020" for each powder tried, but not all powders gave tight groups even with the longer jump, and similarly one of the powders shot a pretty respectable group with the shorter jump. My observation though is that the distance to the rifling can not be treated as a final refinement in load development for the 168gr Bergers in this rifle as it has been when using other bullets. It looks to have an effect as significant on group size as type of powder and charge weight. All the online info and comments indicated that this would be the case - I just wanted to get a feel for it.
Experimentation is at an early stage. I haven't fired off a lot of rounds (yet) so the results are just suggestive, and because I wanted to check several powders I only tried two different jumps rather than the 4-5 recommended in the above link, though it already looks like somewhere close to 80-thou will be OK. I gather some rifles can have more than one sweet spot as well which would be useful - I might be able to find an accurate load that also fits in the magazine if somewhere out at 0.15-0.2" jump also shoots well! I went through 2 boxes of AMAXs trying to get them to shoot and couldn't get rid of the occasional flyer, so the 168 Bergers are my other > 0.6 BC option. Can't shoot the 180s; 1:10 twist, possibly the reason for the AMAX difficulties.
Bookmarks