So with the help of the Campfire search tool, I started using some 7828SSC. I found that 55gr of it behind a 150 would give me groups in the 1" range. I bumped it up to 57 and am seeing larger groups, more in the 1.5 to 1.75" range. (I am no gee whiz with a rifle. I think all of my rifles are better shooters than I am.) But I have no pressure signs and my Pro Chrono tells me that they're leaving the barrel at about 2975, give or take.
The plot thickens. When I was getting velocities like these, it was in the high 80's at the range. Almost 90.
I went on Saturday. 60 degrees. First shot was 2898. Second was 2912. Third was 2925. Hmmm. While these velocities are fine, I have to admit I wasn't so hung up on velocity loss from temperature change, until then. I bought a pound of H4831, and going to try an extreme powder just to see what happens.
I am loving this chronograph. Real data, no guesstimating. Love it.
