Although I don't currently live in Ontario I am puzzled by the comment that the .30-30 was not allowed due to calibre restrictions. My search of the current Ontario hunting regulations found this statement (which has been there as long as I remember)
The holder of a small game licence may not use a rifle of
greater calibre than .275, except a flintlock or percussion
cap muzzle-loading gun, for hunting small game in the
counties of Brant, Elgin, Essex, Huron, Lambton, Middlesex,
Northumberland, Oxford, Perth and Wellington and the
regional municipalities of Chatham/Kent, Durham, the
former regional municipalities of Haldimand-Norfolk and
Hamilton-Wentworth, Halton, Niagara, Peel, Waterloo and
York and the City of Toronto.
This only applies to hunting small game, which really means you cannot use your .270 or .30-06 for hunting groundhogs, or small game.
So, if this is the regulation you are concerned about, and you like the .30-30, then go for it.
As already mentioned, the recoil from a military 8mm mauser is not the way to judge recoil from a hunting stocked rifle with a soft buttplate. Saying that, you cannot go wrong with the .25-06 for hunting deer; just make sure that you are using good bullets and the correct bullet weight.