Re: .45-120 black powder cartirdge?
express, maybe I can help. Are you planning on using black powder or smokeless? Cast or jacketed?
The recoil of a 500gr bullet leaving at close to 1600fps is heavy but manageable. With a hard cast bullet of proper nose design, penetration is more then adequate.
There is no reason that you can't get a good quality "vintage" rifle to shoot 2 to 3 MOA with smokeless loads. Personally, I don't like BP due to the cleaning and possible corrosion issues during a Northern Canada hunt.
Range is up to you but it will certainly work out to 500yds. You will need a good range finder like a Leica. Terrain is usually without trees so picking up a reading may be tough with lesser rangefinders. A very good drop table, every 10 to 20yds, will be mandatory. The trajectory of this type of cartridge is very high.
Pedersoli does make some excellent replicas and they run around $1500 to 1650 Cdn. Sharps and like from the US cost around $2500US. So a sig savings.
You might want to talk to your guide to discuss how the hunt will evolve, the terrain you will be up against, the temp/weather, the range they will let you shoot at.
Others have gone on similar hunts with some basically being "cattle" culls - very short range, not really hunting. Some have been on wild bison and have really had an adventure - they are pretty spooky and will run for a long ways.
A great adventure nevertheless. Just be prepared for WINTER. That also includes gun lubes, bullet lubes, and anything that can fail in the cold.
When are you coming over? Make sure you do the firearms permits very early, like right now. We have goofy gunlaws.