The 3" cylinder can shoot both 3" shells and/or the 2.5" shells. I have the public defender version, personally barrel length is going to make no difference, the shot spreads out so fast do to the rifling you don't gain much by going with the 3" barrel other than being hard to carry. The public defender 2" barrel 2.5" cylinder, even with a smaller grip and lighter weight is very easy to control. As far as the 3" shells go no one makes a good self defense round in 3" shell. It has been shown conclusively that lead shot does not penetrate enough, and often flattens going down barrel and is there for not effective for self defense. The 2 defense specific shells available are the Federal 000 buck that uses 4 plated balls, and powder designed for the short barrel of the Judge, and the other is the Winchester 3 plated disks, and BB shot also has a fast burn powder for the short barrel of the judge. The other downside to the 3" cylinder is it makes the 45LC even less accurate than out of the 2.5" cylinder, and even out of the 2.5" cylinder the 45LC is not a tack driver. The problem comes from the fact that there is so much cylinder before it picks up the rifling. IMO I would go with the Public defender if you plan to carry it at all. There are a lot of Judge haters out there so be prepared. As a snake gun barrel length and cylinder length are not going to make any difference.