For those interested in data for the 250 AI, today I laddered from 40 to 44.5g of R17 with the 117 BTSP Interlock.
THIS IS WITH A 25 INCH BARREL IN A BSA CF2 BOLT ACTION RIFLE.
Top speed on a 3 shot ave was 3044fps at 44.5g. The group at that charge was an impressive 0.8" at 125 yards.
40g - which in my rifle I would now consider a starting load - of R17, gave 2676fps.
