I don't see why it wouldn't work, but I'd give Hodgdon a call just to see if they can offer you any data over the phone as to start and stop loads.
Burn rate is somewhere between 4350 and 4831, or so it seems... maybe a tad faster than 4831, but perhaps (perhaps) able to wring a few more fps out of a bullet without getting into high pressure issues. Look at the 30-06 data for a comparison as to how the superformance works versus the 4350's and 4831's. (they're listing superformance data for the 30-06).
Hodgdon - The Gun Powder People
Probably a workable powder for 200 to 250 grain bullets. They show data for the 4350's also... but I'm not certain you'd outperform H1000 for the lighter bullets in the 338LM.