If you are spending that much in a chassis why not go with a Kreiger barrel and time and true the action.
Well U need a trigger too, machined recoil lug etc and all the good stuff. Farrel steel base would be my preference.
That said if you get a good barrel as in real good it should shoot 3/8 out of the box with a good as in real good setup and minor future work.
I had a non worked 6mm BR in a choate stock that shot 3/4" at 300 yards.
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