The regulations are actually a bit vague on the amount of bolts you need. I've attached the spec, maybe your comprehension will exceed mine. All they go on about is the holes in the safe for the bolts. So if we go on the idea that 1 hole = 1 bolt, the following seems to be the requirement:
2 bolts for a small pistol safe (B1), in either the floor or wall. and 4 bolts for a rifle safe (B2), 2 in the floor and 2 in the wall. (All bolts at least M10x80mm)
But as others have said, don't just comply, rather go overboard. It will be a LOT of admin, stress and drama if your firearms get stolen.
Personally I stick to 6 bolts, with a corner mounted safe, 2 in the floor, and 2 in each wall. I also fill any gaps where a prybar might be forced in between the wall/floor and safe with chemical anchor mix.