My friend is trying to develop a load for his Weatherby in 257 Roy. We started out with H1000 and and 4831. The bullet is a 117 sgk and Winchester primers. The bullets were seated to 3.220. The h1000 gave great velocity 3420, 3450, 3480 fps for 73.0, 73.5, and 74.0 grains respectively. About 1 out of 4 rounds would have soot near the primer, be it a ring in the primer pocket or smudges on the backside of the base. Primers were not flat at all and extraction was easy. Cases were once fired factory rounds.
Also the groups were about 0.4 vertical but 1.7 horizontal.
The 4831 was about 250fps slower and the accuracy was a hot turd.
Thoughts?
Last edited by Bisley; 01/22/20.
