I built one off of a Stevens 200. Used a stainless E.R. Shaw in 1:10 finished at 22”. I LOVE IT!!! It goes with me everywhere, and probably has drawn more blood than any other rifle I own.

I shoot 85gr Sierra GK HPBT in front H335 at 2705 FPS.

Doing it again, I would consider:
McGowen barrels
1:8 twist
20” barrel