the rubber on the 302 bar was designed to ease sliding if a stray lead pellet got caught between the bar and the guide. it would allow the pellet to roll along. old bars w/o it could actually stop the bar and jam the operation. ive converted the old 600jr's to the new rubber bars and find them to be a little tight. the tightness of the bottles will also effect the operation of the bar. whatever amount you pry can be countered with the brass washer and screwing the bottle down tighter on a new rubber gasket. good luck.
