Our BGR association does have a Howdah pistol competition in its rules.
1. Minimum calibre .375
2. Single or double barrels
3. Smooth or ball rifling
4. Minimum muzzle energy 1000 ft.lbs
5. Minimum 300gn bullet weight

Firing sequence - 10 shots at either 25 or 10 yards at a "tiger' target - if possible

So if you have 300gn at 1250fps then you exceed the 1000ft.lbs target & in say a 4-5lb package....it certainly would be lively!