A barrel is a barrel is a barrel. Choosing one is all about looks and weight. The biggest factor affecting accuracy is you.
I overbore with a 693, always have, always will.
Ive used smaller bore barrels, and I get no upgrade in my aiming ability, but I do get the odd random barrel break, which sucks. Always at the wrong time aswell (never at the chrono lol). So I don't try to match the paint to barrel at all.