It's been a very long time since I've had any MRP. I have not seen it for sale in my usual haunts and I guess I have not looked for it in many years. To be honest, I thought it had been discontinued a long time ago. But I have a few pounds of RL 22. It is one of the most accurate powders (H1000 too) in my 300 WM.
The bottom line for me is that I've not noticed any variance of burning rates for RL 22 in my 300 WM.
