RS52 is an excellent powder giving higher velocities with lower pressures. Going on what my Exe F class lot tell me it is very stable temp wise as well.

The powder is steeped in nitro rather than the normal mixing methods which apparently makes it more consistent and easy to control (in terms of process).

I have been using RS52 for a while in my 5.56x45 ammo and it shoots well. It also meters rather better than N140 which is nice for extruded powder.