First range report to this.
Gun: RAR
Bullet: Barnes TSX 275
Brass: Starline
Primer: Rem 7 1/2
Powder: N120
COL: 59,4 (front side of first groove)
Temp: about 18C
Load(grains) Velocities
35.0. 1766. Lot of soothing
37. 1689. Lot of soothing
38. 1733, 1746. Soothing
39. 1800, 1804, 1769. Minor soothing
39 grain load did 15mm group @50m with old scope and 4* magnification.
Will fine tune loads from 39 to 40 grain and test more. 40 grain is about full load, and anything over it will be compressed load.