We did 2 control groups, using Reloder 16, same brass, 26.5 grains, as this load is already established as consistently good. And it did it again. @ 200 yards out of the AR, 1.5 & 1.6 is great, we will take that.
Reloder 15.5 is another story. It has better potential than the Reloder 16 because you can fit same amount in the case as the Reloder 16. So since Rl16 we were using 26.5, you can see there is a lot of space to go. This makes RL 15.5 ideal for Valkyrie. And seeing that we got the 80.5 Full Bore's to do excellent 1.3" group first time out, with no tuning, that is as good as we could hope for. The ELD-M Hornady matched the RL16 load too, at 1.6". Not tuned. So great potential. And look at that:
RL15.5 24.0 grains is about 2664 FPS
RL 16 26.5 grains is about 2664 FPS
2.5 LESS grains to get same velocity. That is great.
This barrel is a Rainier 22" Ultramatch 2. Its like 1:7.5 twist, so perhaps the 85 RDF a little outside ideal
So we have a winner here folks. Reloder 15.5 is great for Valkyrie with large potential. Take a look at the data below.
We got 4.7, 5.0 and other single digit SD's. with 2 ES of 12! that is really top tier. With tuning, it is sure to be consistent around 10 SD, and ES around 20 (if you shoot enough bullets) That is all you could hope for in a powder, and in a narrow class of powders that can compete with that elite area.
Perhaps the largest competition for Reloder 15.5 is simply VV N540.