Re: .303 vs 30-06
30-06 - full stop. That is all you need. A .303 is okay and it has probably harvested more moose/deer meat than any other cartridge in Canada but it is very dated and most rifles are quite old and will 'tend' to be more inaccurate. You will be able to get 30-06 and 303 ammo equally well but a 30-06 will serve you better across bullet weight range and being able to tailor your needs to what you hunt.
Regards,
Ltbullken
Freelance Wildlife Population Manager
Animals - If you can't eat 'em, wear 'em!