Sicero, What I plan to gain is that the 204Ruger is a too long for the clip on the 527. The bullet needs to be seated very deep in the case. Also rifle has a long throat and I can't get anywhere near the lands. The 20 Tactical is just enough shorter that I think it will work better. I plan on using a reamer with a shorter freebore,which will also help. I also believe the 20 Tactical is closer to optimum case capacity for a high speed 20. Plus it has a longer neck and plenty or good brass to pick from(223).This will solve my problem and be a superior cartridge. Dave