I have Pachmayr Grippers for both J and K frames. They are the cushiest grips I own and definitely deserve the label "full size." When I want to do a LOT of shooting with a J frame, it's what I put on.

It's also what I put on the time I decided to try a single 357 Magnum round out of a J frame, just to see what it would be like. (It still hurt.) I wish they made 'em for the Ruger LCR, as I discovered yesterday that almost all of the 327 Federal Magnum rounds with any real punch run from uncomfortable to painful to shoot in that very light little gun. I was doing chronograph testing of a lot of different factory rounds looking for a balance between power and tolerable-to-shoot, and a bigger, softer grip sure would have been nice.