I own a 12 FV in .223 and my buddy has a Stevens with a Mcgowan barrel in .223 and SSS trigger and his gun is more accurate than mine. It is almost not fun to shoot his because it is so accurate. As far as twist, in a factory savage barrel with a 9 twist I can shoot the 75s. Although I hear that it is hit or miss if it will stabilize the 75s with the 9 twist.