The .17Predator is kindofa PITA to make brass for from .223 Lapua, but its a fun little rocket. Short neck special, it allows for quite a bit more speed than a .17Rem or .17-223...
If you have .20TAC brass available, necking it down will get you in the .17hotrod game with a .17TAC.
Or, as Phil suggested, do a .17-204 and win all around with the same ease of brass forming, AND enjoying more room for powder boom!
Love my .17Predator, but a .17-204 is the bigger case, if you want to push the envelope with speed.
From what little know, once you get a 30grainer clockin' 4K, you're squarely in the "sweet spot" for killin' ability without overly stressing the jackets of those tiny .172 cal. missiles. Recently shot my .17P over my Magneto V3 in the cold, and got 4055 from a 30gr Gold. Temp was 30 ° , out of a 24" Lilja 1:9tw...
The little .17 hotrods sure are a pisser!
Watch this video, at the time it is what sold me on building a .17Predator. I still get a kick outta watching it!!!
http://www.rmvh.com/Movies/17with17.wmv
A .17TAC will likely allow the same performance.
Have fun!