No - I don't have a Baikal. The loads I was running were from a bolt gun chambered for the .458 2". Due to it's chamber length, it was about equal to a .45/70 with a short, but definite leade before the throat. With a double I'd probably stop somewhere around the 50gr. level of H4198 or up to 100fps higher speeds with a slightly slower powder. The bolt gun easily allowed more powder than that, but that isn't being recommended here. We got some wonderful velocity/pressure comparrisons with H335 but used John Buhimller's old trick of a primer cup-down on top of the powder underneath the bullet. Not for the faint at heart, but it was safe as long as loads are just over 100% with only a small amount of compression. In the 2.1" case, 60gr. H335 gave us the same speed at 68gr. without the extra primer. It was Old John's answer for improving ignition and powder burn in the straight cases. The 'extra' primer merely helped burn the powder, which is not easy in a straight case.

We used the same load for 350gr. through 510gr. bullets. The throat in my rifle allowed seating as if the case was 2.3" long, not 2". A normal LeverGun-type chamber and throat requires a 2.55" OAL, ie: no throat to speak of. With a short throat that does not allow seating the bullets out, one will have to work up very carefully. That we were able to use the same loads with 350 through 510gr. bullets, shows the pressures were 'probably' quite reasonable with the 350's.

I would not hesitate to working up this sort of load from well below when using a double rifle like the Baikal, only stopping if pressure or regulation brought a halt to the testing. One Must kow what one is about. This is not for beginners. Were I in that situation, I'd refer only to the manuals that keep pressure down to well below 40,000PSI. there is plenty of data out there for loads up to 35,000PSI - unfortunately, one must adhere to those loads exactly or pressures can rise unpredictably. Switching bullet manufacture can raise pressures just in itself. A friend switched from Speer to Barnes FN's, both in 400gr. and got 150fps higher velocity just for changing bullet makes. Fortunately, the Marlin shruged off such foolishness & still showed mild pressure. 2007fps from an 18 1/2" barrel is not particularly fun to shoot a lot of, especially over the chronograph. The same powder load went 1,850fps with the Speer bullets. The powder used was Re#7 - a good and generally accurate for 350 and 400gr. bullets in the .45/70.

The moose noted were Canadian moose, running 675 and 735 pounds hanging in quarters. Descent size, in other words.