Something was bugging my memory... Found it!
The 1894 series of Marlins (in .44) have a 20inch barrel with a 1:38 r.h. twist!
With that slow of a spin, the Marlin will not stabilize 300+ gr bullets. OK, at 300gr, the bullet is barely able to be stabilized, but anything heavier is not likely to track very well.
Practically speaking, I wouldn't count on accuracy for anything above 270gr. Depending upon what you plan on hunting, this will prove to be somewhat of a limit.
I've developed some hunting loads for my SBH that use a SIE 300gr SJFN. They are very accurate at 100yds with the SBH, but are erratic in my Marlin.
Something to remember when working up loads for both your pistol and your levergun.