Are you competing or just plinking?
I have used most commercial actions and military actions.
My favorite is the Enfield P14/17 actions as they can be easily modified to function like a commercial action and are strong. Easily supporting the weight of heavy match barrels.
They are also capable of very good accuracy. All are sub MOA with the best depending on the barrel and install. Consistently 1/4 to 1/2" has been the norm with large magnum LR cartridges.
Not BR competitive (consistently in the 1's) at least with the time and work I have spent on them, but certainly very capable. Also remember, that I am not using top level BR barrels either.
The vanilla tweaked Rem 700 action would be a very nice place to start. The savages are also proving to be good platforms now that there are better triggers for them.