I did some testing with Ramshot True Blue. Its burn rate is close to 3N37 which I was using. True Blue is very fine much like SP2. It meters very well with the Arradondo powder bar.
I worked up a load for my open blaster. 124 gr armscor bullet, 8.7 grains, winchester small rifle primer, Armscor Brass, col 1.245. Chrono'ed at 170 PF. If you try this power start at about 8.2 and work up. My blaster has a hybrid and a aggresive comp.
Results.....I LOVE IT. Once the last of the VV is gone, I will be using True Blue for open. There are several top shooters in the northwest using Ramshot Competion in there 40's and loving it.
Give them a try.
Ktyler