RE: rem 7mm mag and RL22 max load
My Barnes Manual shows a Max load of 70.0 grains of RE-22 for a velocity of 3212. IMO you are asking for trouble trying to exceed the recommended Max. Barnes does say that the TXS may require a bit over max load for the regular X bullet but you are getting close for sure. If you need more velocity, I would look at the 7MM STW.