Its common for many people to have specific groove barrels that they claim is best. I happen to like 3 groove barrels but dont have one at the moment. Im wanting to order a three groove barrel but I want to know some specifics first.

On a 3 groove barrel, are the grooves and lands equal in size? Here is a picture of what Im talking about.
http://i5.photobucket.com/albums/y15...relgrooves.jpg

The bore on the left has very robust rifeling while the bore on the right has thin rifeling.

Will robust rifeling create more pressure?
Someone give me some 101 on the toppic please.