Originally Posted by Broz
You must be getting a mark from each side of the lands. I am betting it is a 4 land barrel. Your velocity sounds pretty close for a 24" barrel and 78.5 gr of H-1000. I feel you are close to or a bit over max though. So you may want to keep that in mind for hot weather shooting or further development.
Jeff, I see what you are saying however each one I counted was a bright band/indenture with two sides and dull non touched copper in-between each of the bright eight bands. It might be possible for the bullet to have bounced giving two sets of four, but they were equally spaced. I am not familiar with Kreigers build standards so I cannot say for sure. I do know it is a 1:10 twist.
I agree on the powder. I have checked several load sources and the max I found for a 300 Win Mag. was 79 grains. I plan on stepping back 2 gr. and going up in .3 gr. steps to do another ladder test looking for a better node for the Bergers. The best grouping I got from the range today was .040 off the lands so I think I will hold that and drop back to 76 gr. of H1000 and build up in .3 gr. increments to see if I can hit a node along that path. Houston is hot right now too.