I just bought a custom built 7mm RUM built on a Remington 700 action with a hart barrel. The man I bought it from said that it shot great with RL-22 (90 gr.) with a 140 gr. nosler BT. Well it didn't. Where do i need to go from here? What powder do i need to try? I would like to shoot the Barnes tipped triple shock but i'm very open to suggestions. Thanks in advance.

I use 87gr H1000 under 162gr SST oval 3.620 and 140 gr gameking over 94.5gr of h1000 oval 3.600 "this gives me a 1 hole group that can be covered with the base of the cartrtidge". They will barely fit in the magazine. I hope this helps you.

Did you use a different primer then he did?
The big RUMS can be sensitive to primer changes.
If you are using something different, try some FED215's.

The RUM case is very primer senitive. I use the Fed 215 I also have used CCI250 DO NOT USE THE CCI 200 They will not work. If you search 7mm RUM you will find several threads where I asked for help on reloading for this cal. I think they are on page 3 of this thread. A S is a great source of help. The loads I gave you have just been developed I went throught a 1# of H4831sc and 2# of H1000 getting it right. I hope this helps you. You can also check Steves page for more load data for the rums.