I called and talked with MGM about a barrel for the 44Mag, they recommended the 20 inch. I went with the bull barrel option with a 1-20 twist, should be able to stabilize any bullet.
Good call - the 1-38 twist levers are severely limited in ammo choices. My 1894 could not stay on paper at 100 yd with 300 XTPs [and I mean a 18" x 18" sight in target.] It was marginal even with 240s.