Since I'm living in Indiana right now, seems the only thing my Marlin does is stand in my gun cabinet. A shame really, but opportunities to use rifles here are limited to groundhogs, coyotes and the like. Not that it wouldn't be fun, but I have other rifles that are better suited to those uses.

My load of preference has been 49 grains of IMR 4895 (I think) under a 300 gr Hornady Interlock JHP. I don't have a chrono, but I'd guess it is close to the load you mention, based on what I've seen in the charts.

It is all the gun I needed to chase deer and black bear in NH, where I'm from. Not too bad for recoil either. Set up with a peep sight it is very handy and fast to get on target in the thick stuff.