I have an 2x4 Instroke buffalo series case,I think the internals are the same as the premiere series.The diameter of the shaft tubes are roughly 7/8".They will hold a normal diameter shaft firmly with no play or movement whatsoever but not so tight that its difficult to remove the shaft.After about three years use on my case the shafts and butt will slide out slowly under their own weight if the case is inverted with the lid open. All my shafts are 29" in length and i still have 2 1/2" of room from the end of my shafts to the top of the case, so extra length shafts or joint protectors are no problem whatsoever.