-
A pound-cast of your chamber and throat will tell you what you need for both brass length and bullet diameter.
A marked cleaning rod and a tight patch will tell you your rate of twist and what bullet weight you can get away with.
It's a great round that gives more mass than a .30-30 and more (or equivalent) sectional density than the lighter .458's and is pleasant in the recoil department. Guys use the faster twist models with heavier spitzers for competition at distance, but that's a matter of being on a known-distance range. For hunting, I'd regard it as the rainbow trajectory round of the 1800's that it is and treat it as a 150-200 yard timber gun.
It should do the job on elk, but I've come to the conclusion that if the hunt is going to be distant, expensive and/or difficult, the gun will be stainless, synthetic, and with an effective point-blank trajectory of about 300 yards. If I'm shooting them out of my backyard petunia patch with a resident tag, that's another matter.
-
Jhon.... I'm in the same boat. I've been a visitor to the site for quite some time but just recently joined. The amount of information here and where it is withering.
We shoot a short range single shot (BPRC, Buffalo gun, etc.) to 300 yards and earlier this year I started moving from the 45/70 to the 38/55. I got a Taylor/Uberti High Wall.
The first outing was a complete disaster and at 50 yards the bullets tumbled in sideways. So my guidance is first understand your groove/bore diameters (in my case is 0.379/0.373 and twist rate (in my case 1:18). This alone will start to put you on the path on the type/weight of bullets and appropriate muzzle velocities.
As a note, be careful there's a lot of confusion and misinformation online and even in the reloading books concerning the 38/55
