This rifle only likes WW296 and small light bullets.
I don't get hung up on specific powders or bullets. I do have some favorites that I like to try first. Lil gun powder and 40 gr V-max bullets for example. My .223 and K-hornets love the V-Max, but nothing likes the Lil Gun.
In this rifle I did want to shoot 52 gr. Barnes bullets, but all they would do was keyhole. This is a real finicky rifle.
All I can do is tell you is try everything listed in the load books. If your concern is not finding Mashburn Load data, use Bee data. Start with the middle loading and work up from there to the Max Bee load. If you don't find a good load by time you get there you need to look elsewhere.
If you don't have Wolfe Publishings books on Wildcats and Petloads and Both Volumes of P.O. Ackley's books get them. Ackleys books especially if you are going to play with wildcats. Don't pay much attention to the load tables in the Ackley's books other for starting loads. But do read the chapters on improved cartridges. You get these books from Mike stegen at
http://www.gunbooksales.com/Only change one variable at a time. If you find a need to use some specific powder. Then build some test load using several different bullets, using just that one powder.
Don't start at max load, most of the time you are beyond the best load by time you get there.