The instance I reported on in GUN GACK II took place several years ago, when I did an article for Handloader magazine on the .270 Winchester.
The batches I had of RL-22 and MRP at the time looked exactly alike, and got the same muzzle velocities, with the same bullets, in the pair of test rifles I used, a Winchester Model 70 Featherweight O'Connor Commemorative and a Ruger No. 1B.
Not too long before doing that article I had talked with the head of Norma at the SHOT Show. He admitted that MRP was the same powder as RL-22, but that he believed MRP was more consistent from lot to lot.
From all that I felt comfortable in claiming they were the same powder--at least at the time. One or both may have changed since then.
