I have really enjoyed this thread. Thanks to all the contributors for such a good discussion.

I have limited experience compared to most that posted. I used R22 in one of our .257's until I had high pressure on a 95° day. The combination of the ambient temperature and chamber/ barrel heat caused a very heavy bolt lift. This was in my son's. 257. I use H1000 in mine and never experienced that. I switched over in his rifle and no issues under the same temps.

I am done with R22 and R25 for that matter. If I only shot during the winter it might be fine but why use it when there are other choices?

Now days my main powder supply primarily consists of H1000, H4350, IMR 4350, Varget and TAC. The only magnum that I shoot is the .257


Faith and love of others knows no mileage nor bounds. That's simply the way it is.
dogzapper

After the game is over, the king and the pawn go into the same box.
Italian Proverb