If you want to extend the inner barrel for accuracy, don't go tighter than 6.04/6.03. It should increase your grouping a little, but not much. A properly set hop-up with a good air seal and bucking is your best shot at BB stability. Also a the tighter the bore, you may get an increase in your FPS. So watch out for that.
ďREALITY IS LIKE A STONE. TO MANY ITíS HARD AND COLD, THEY CANíT HUG IT OR EAT IT, IT ONLY FRUSTERATES THEM AND DOESNíT DO THEM MUCH GOOD. TO OTHERS ITíS STRONG AND DEPENDABLE, YOU CAN BUILD WITH IT, BUILD UPON IT, OR WORK WITH IT, ALSO USE IT TO SMASH PEOPLE IN THE FACE.Ē