I put a Shilen on my .243 Ruger a few years back...I went to a 24 inch...I got the same taper you are talking about, a little heavier than standard, I can't recall what they called it....Go to
www.shilen.com I just popped over there...they have all the info you need, contours, rate of twist, etc....
Another thought...I noticed you are in GA....I'm in NC...If you haven't tried the 85gr Sierra GameKing BTHP on deer...you need to...especially if you have shots past 200 yards...Federal loads in their Premium line if you don't reload.