When I wanted to go smokeless I took Lundy's advise and checked out the Dougsmessesageboard link. I read and learned everything I needed to know then a TC Encore smokeless converted 45-70 barrel showed up for sale for the price of the conversion only so I bought it. It was as new. And shoots great and already took 2 deer in 2 years.
I got my tested load data from the forum. I already had a TC Encore barrel threaded for a TC Encore blackpowder breachplug and the guys told me of a machine shop that made a Savage smokeless style that would fit my TC Encore threads. That also worked out great for my 2nd conversion for the grandkids.
That forum is the place to go for info on smokeless ML firearms. Some of those guys are just pure experimenters with all the proper pressure equipment.