I tried some T7 years ago and did'nt like it because of the Crud Ring, so I stayed with Pyro RS Powder. Im shooting the same Bullet as you, 240gr XTP, T7 or Win W209 Primers and the Harvester MMP HPH 24 Sabots. No Problems without Patching between shots if need be.
I have yet to try BH but if your looking for a Powder that needs little to no Maintenance, BH is the way to go.
Also there should be no need to have a quick second shot with your MLer, the first shot should have been on the money. A Hurried second shot at a aleart animal is going to be worse than the first one if you can even get one off that's a good one. And Im not talking about a second follow up shot to do what the first shot should have done.
Best of Luck and get some BH and your Crud Ring will be no more.
(BP)