If you're thinking about changing cartridges but keeping the same gun, check out my new FREE tool just released within the last couple weeks, the AmmoGuide ReBarrel/ReChambering Guide at:
http://ammoguide.com/cgi-bin/aichamber.cgi
(If you don't have an account, just press "Enter as DEMO" on the login screen - the tool works for anybody.)

It analyzes the shape of your current chamber chamber against the shape of the other rounds in the database and reports results accordingly. Also gives you other options regarding allowed action length and if the bolt/extractor will be modified. Being a Guide, the tool may suggest candidates that you will immediately reject for one reason or another (all it considers are case dimensions), but hopefully the candidate list will include some good suggestions you never thought of. That's what the tool was designed to do.

The Guide allows you to compare against all other rounds or just one specific cartridge. Example output in the latter mode:


Hope u like and it proves helpful, Mike