Yes, im taking a shot in the dark here.
Given tbat its Scotland and the English heritage of hunting there is largely focused on game stalking (known to the US hunters as still hunting or spot and stalking)
The Stalking Rifle, a design of rifle focusing on relatively low recoil cartridges between 6mm and 8mm typically. These rifles are designed for light weight and accuracy at distance. Unlike driven hunting, game stalking is usually a slow and methodical approach with the intention of taking a single precise shot.
The reload animations should be like the Malmer, Olsson, and Vallagarda. Older designs will usually have 5 round magazines
Calibers are chosen based on the game mostly in the area the hunter chooses.
For Scotland I'd expect
6.5x55mm
Or
.275 Rigby/7x57mm
Ironically both of these should covers classes 3-7 neatly (the could do 3-8)
Another good choice would be the 9.3x62mm cartridge covering class 4-9 with much better penetration than 7mm (if the .45-70 was accurately depicted it would be better penetration wise)
And yes, I fully expect this to be wrong and disappointed with it.