I've had several rifles walk a target unless the barrel was floated so mine get floated before they go to the range for load development.
Bedding? It can help, but only one of my rifles is bedded. I haven't found it necessary with my Rugers, although I think the angled front screw locks the action in place much as bedding would if it it properly tightened.
Good trigger can make a big difference.
Trued action? Again, only one of mine are trued, the same one that is bedded, my 6.5-06AI.
A perfect crown undoubtedly helps but I think a good barrel is generally more critical than a perfect crown.
A good scope with high also helps. I find I shoot much better with a 14x than I do a 9x of similar quality, better with a 9x than a 7x, better with a 7x than a 4x, and so on. A 20x improves things even more as far as achieving a consistent aimpoint that is as small as possible.
OK, I can count and that's 7 items, not than 5. In terms of importance, the order in which they go depends on the rifle.
