Nice rifle. I have owned a couple 1894's in 44 mag. As was stated, sometimes they can be problematic when feeding SWC's. Mine were best with rounded profile bullets. They can also be feeding sensitive to bullets heavier than 240 grains or so because of cartridge OAL. I don't know if the cowboy has the same barrel twist as the regular guns... If it does, then you may have a problem stabilizing bullets much heavier than 240 grains or so, as the twist rate is on the slow side for heavy bullets. For factory ammo, mine always liked standard Winchester white box 240 grain soft points. I used quite a few cast 200 and 240 grain RNFP reloads as well, both in reduced and full power loadings with excellent results. Whether micro grooved or ballard rifled, lead will work well if sized correctly. Pictured is my stainless steel 1894, pre-Remington.
Larry