My objective was identical velocity of my 300 grain load {2450} plus similar zero using a light bullet for 9.3x57 performance from the larger case.

I got that with no problems with ignition, etc. 5744 does NOT act like 4198, 4227 or 2400 though all of those can be used to obtain similar objectives at times with appropriate loads. The big advantage of 5744 is that it burns well and I've never experienced a single hangfire with it. Not saying it isn't possible, but the powder is designed specifically for light charges in big cases.

One other feature of the load is that because powder charge is light, so is the recoil. Seems about like a .30-06 with 180 grain load tho the actual ballistics duplicate the 220 gr load in the '06.

I believe a 5744 load could be worked up easily for heavy bullet that would be cheaper {less powder} and a bit less recoil than the slow-powder/full-case load.

Do you have any problem with unburnt powder in that H1000 load?

{and by the way, I have been using IMR7828SSC with great results in my .264 Win Mag, another powder that might work for your objective of full-case/reduced velocity load}.

Your approach reminds me of the slow-powder/full-case/cast bullet loads that many have used with very fine accuracy, tho with some unburnt powder at times.