Paul5388 is pretty much on the mark with the relationships between N and RL powders.
The N powders 'may' have a few more steps in the process and definitely way more quality control.
Compared to MRP, RL-22 is floor sweepings
Though it is the 'same' powder. The RLs, I think, are way less quality controlled. Kind of like factory seconds.
However, they are GREAT for velocity and accuracy. Norma powders are difinitely better but Grafs is about the only supplier and its a once a year order.
Velocity/pressure variations from lot to lot of RLs is pretty extreem some time.
"The" load for my 338 Win was RL-22 w/250 gr bullet @ 2800 FPS. It was right up there in pressure. Bought another can of RL-22 and didn't "rework up" the load, just loaded and fired. Velocity went to 2930
Shot great, showed no pressure signs over my standard load. Can't find any more of that lot.
Thus designated a new cartridge: 338Win/WUM. I then rebarreled to 338 RUM just to see the difference.