I built mine on a new WIN 70 CFA in 300 WSM. This is a better approach in my opinion because action was designed to handle larger case from the git go. No bolt section reduction required to handle Jeffrey case. Gunshop purchased barrel, stock, trigger group. This paid for more than half the cost of donor rifle. They keep parts for people with damage rifles or worn barrels.
Put Lilja 3 groove 26" varmint pattern barrel on rifle and what at the time was the first production MacMillan stock for that action. Jewel trigger rounds out package. 26" barrel gives a little more velocity, but is pain in gun safe not designed for same.
Had USO make custom picattinny rail for rifle. Initially had 3.2-17x44/58 shown, now has 3.8-22x58. Gives touch more power and better low light function.
Rifle fires 180 VLD Berger fairly accurately using F215M primer and VV N165 powder. Velocity with 180 around 2830 or so. see 100 yard development target below.