I've mentioned this before, but here in UK we have very strict lower limitations on the muzzle energy and, in Scotland, mizzle energy AND velocity -
SPECIES | MIN BULLET WEIGHT | CALIBRE | MIN MUZZLE ENERGY |
Red | | | |
Eng & Wales | – | Not less than .240 inches | 1,700 foot pounds |
Scotland | 100 grains | – | 1,750 foot pounds (min muzzle velocity 2,450 feet per second) |
N Ireland | 100 grains | Not less than .236 inches | 1,700 foot pounds |
Fallow | | | |
Eng & Wales | – | Not less than .240 inches | 1,700 foot pounds |
Scotland | 100 grains | – | 1,750 foot pounds (min muzzle velocity 2,450 feet per second) |
N Ireland | 100 grains | Not less than .236 inches | 1,700 foot pounds |
Sika | | | |
Eng & Wales | – | Not less than .240 inches | 1,700 foot pounds |
Scotland | 100 grains | – | 1,750 foot pounds (min muzzle velocity 2,450 feet per second) |
N Ireland | 100 grains | Not less than .236 inches | 1,700 foot pounds |
Roe | | | |
Eng & Wales | – | Not less than .240 inches | 1,700 foot pounds |
Scotland | 50 grains | – | 1,000 foot pounds (min muzzle velocity 2,450 feet per second) |
Chinese water deer | | | |
Eng & Wales | 50 grains | Not less than .220 inches | 1,000 foot pounds |
Muntjac | | | |
Eng & Wales | 50 grains | Not less than .220 inches | 1,000 foot pounds |
Add to that that the chances of actually being ALLOWED to have a muzzle loader that meets any of those figures is to all intents and purposes nil.
BP c*r*r*d*g* firearms would just fit the bill, muzzle energy-wise, but not velocity, especially in Scotland, where so much deer shooting takes place anyhow.