I agree its weird we can use sabots and Powerbelts, as long as the actual projectiles are pure lead, but Olympia like many state legislatures aren't terribly swooft!
Will try the musket caps with T-7 pellets and loose powder. Had heard that caps of any kind were supposed to have trouble igniting the pellets. After reading the thread about whether to use two pellets or three (50 grain pellets), it would appear either version of T-7 should work okay, unless to fine-tune a load using the loose granules. I had originally planned to use the loose powder to tune-up a load, but the thread about the 2 vs 3 pellets was pretty convincing. I'll go with 90 to 120 grains, loose or pellets depending on what the rifle likes.
One thing I have learned becoming familiar with my rifle is that the Harvester-brand sabots appear to be VERY SIMILAR with the MMP sabots, the T/C sabots, Nolser sabots and I'm guessing Buffalo sabots. The sabots and bases look identical except for the different colors of the plastic. Is it possible that Harvester makes all the other sabots? Only changing their cosmetics slightly?
After studying the different loads and reports from Hornady and posters on this forum, 90 grains or so should propel the 240 grain sabots close to 1800 fps and over 1000 foot-pounds at 100 yards. Midrange trajectory is 1-1.2 inches, which sounds very adequate to kill Mr Whitetail..