otherwise affixed to the grip holder 418 bearings 408 are positioned within the apertures of gear holder 414 grip holder 418 extends through bearings 408 which provides for a stable rotation of grip holder 418 shims 410 are positioned between follower gear 412 and bearings 408 to ensure a space between follower gear 412 bearings 408 and gear holder 414 to reduce wear or rubbing of the follower gear 412 against the same likewise grip holder 420 is positioned through apertures of another gear holder 414 and an opposite end of chamber body 404 a follower gear 412 may be press fit or otherwise affixed to the grip holder 420 bearings 408 are positioned within the apertures of gear holder 414 grip holder 420 extends through bearings 408 which provides for a stable rotation of grip holder 420 shims 410 are positioned between follower gear 412 and bearings 408 to ensure a space between follower gear 412 bearings 408 and gear holder 414 to reduce wear or rubbing of the follower gear 412 against the same those skilled in the art will appreciate that the gear holders 414 may be attached instead to the chamber holder 320 and modified to interlock with chamber body 404 hollow grip holder 418 and 420.