FWIW, I shoot the 300gr Nosler PP Partition in my 22" barrel, velocity is 2425fps, the same load in my 32" BC barrel is 2450fps, so it depends on the powder as to what velocity you'll get in the 32" barrel, some won't make much difference as in the H4198. I'm working on H4895 in my .405 Winchester Target, 45-70 and 45-120 BC barrels, it seems to have a lot of promise as to utilizing the extra barrel length. I've shot a lot of 5744 in the 45-120, it is not position sensative in the least and that's with about a 50% or less load density!! The nice thing about the Hodgdon Extreme powders, I don't have to worry about temperature changes affecting performance, unlike a lot of other powders.
Tim