35 Whelen Nut. The reason for the increased velocity ISN'T increased pressure. It was explained to me that the older powders have a parabolic pressure curve where as the newer powders like CFE223 and Hogdon superformance have a pressure curve that doesn't peak as hit but maintains the pressure over a longer period of time. This is what enables the newer powders to give a higher velocity at a similar or lower pressure. If it wasn't safe I don't think powder companies would load it. A 250 grain hornaday roundnose at 2,700fps puts a lot of hurt on an Oryx
My rifle must be a freak in the accuracy department as 5 different shooters using a variety of bullets ( 2x225gn accubonds, 2x225gn Woodleigh PPSP, 2x250 gn hornaday roundnose, 2x 250 gn hornaday spire points and 2x250gn Speer hotcores)) into a 1.2 inch group at 100 yards. My PH wanted to buy the rifle.
It's a plain Jane Stevens 200/ Savage 110 with a 25 inch MAB stainless barrel 1in 12 twist, rifle Basix trigger Leopold mounts and Zies terra scope. The 225 grain accubonds and woodleigh projectiles at 2,800 to 2,950 fps give between 4,000 and 4,300 for of muzzle energy. Yes these velocities seen high but with the newer powders available now they are SAFELY available.
