I purchased my son for christmas last year a 7mm RUM.I've been working up loads with H 5010 and H 870, based on the 175gr weight. I've gotten a safe max vel of 3100 ft/sec. What I would like to have your opinion on , Is this about the vel you guys get with your ultra mag. This is a 26" barrel, and my 7mm STW gets 3050 ft/sec with a 24" tube.

I get 3100fps w/ my 7mmDakota from my 26" Ruger #1 w/o bending anything. The 7RUM is so overbore, it's tough to get much faster than a STW or 7mmDakota. Have you tried a RL25 or H1000?

No. I've got a good supply of H870,and H5010. I would only try others if someone was getting a significent increase in vel. My accuracy is good with the mentioned powders.