you will get lots of coments saying one particular barrel is better than the rest and also comments saying different bores sizes dont make a difference etc etc..
ive tried loads of different barrels and the ones i personlay think work well on the ego is the un1tec 3 piece kit 3 choices of bore 685, 689 , 693 all u need really
I Have an SL which you get the backs 685, 689 & 693 but still use my unitec barrels
whether there's a major difference i dont know but the unitec barrel seems to shoot a bit straighter