Yup, Old Wolf, you have hit on the main point.Its the compressability of RS that makes it work so well in my OA. It has a nice mix of power,accuracy and convenience. Its not the most powerful or accurate load, but it is the best compromise of both that I have ever found.It is also easy to load,no measuring. It is my hunting load. Results may vary for others, but I have tried about every powder and filler combination out there. Using finer 3f or pistol pyro will get ya more FPS, but my gun starts throwing big groups with em. Filler and 3f or 2f will put em all in the same hole,but they are too low power to hunt with. Try Rs, if your gun likes it, yipee, if not, no harm done.