I'm building a 4"PPC bbl gun for double action shooting. I've been given a piece of douglas bbl with a 1-18 twist ro use on this gun. I'll use it mainly with 158 gr lead round nose bullets or 148 hbwc at 50 ft. Will this twist do it or will I need the 1-14 thats available? I'm using a pre war frame for the long action. What twist does S&W use in their .38 spec? Thanks, Larry