The Parker ballistic extremes are a very good bullet. Knurling the bullets for sabotless takes alot of extra time. Especially to make them right and consistent.

BH209 is a lot better powder then you give it credit for. RB was really doing a lot of research on it trying to figure why and how it was so good. It still shot the light bullets extremely well when the other smokeless powders would not.

Your ULA with 42grns of N110 and a 275grn Parker BE
will do the job on most animals with out a doubt. No need to change the bullet and it works. When i get mine back, i plan on trying the ULA with the 275grn Lehigh. If they dont shoot well theres always the 277grn Lehigh bullets. I think both will do just fine with the Short Black harvester sabots.

Ive got both the Lehigh 277 and 275 ready to test in the ULA with N110 and 4759. Ive got a BUNCH of Parker 275s too. I even have his 225gr XPB load and the Harvester Smooths. I shot 43gr and the cheaper PT Golds and it was crazy accurate.

I REALLY want the Lehigh to work even if its only 2200fps. I dont care if its smokeless or BH209.

I like the idea of the 1-26 for both the 50 and 52cal. Its pretty much a Knight exclusive twist already in the 52cal. It should give a small edge in the 50cal too and be kind of a selling point.

The problem with a 1-20 45cal is been there and done that. It bombed and many people wont forget even if it was just the marketing of a 155gr@2500fps that made it bomb, not the twist. Its fine for a 200gr or larger bullet, probably really good with a longer monolithic or even conicals. Even if just by a marketing view point the 1-24 would move away from that "bad ole" 1-20 that some wont forget. Even Cecil at PR still rags on the 1-20.

It will still give most of the advantages though and no one makes a 1-24 45cal so it would be another "exclusive". I wonder what a Lehigh 200gr would weigh in copper?