When I had to tighten one . I used a spring loaded clothes pin gripped with just my hand . I would " snug " it then give it about 1/16" more . I didn't say 1/16th of a turn , just nudge it about 1/16" of an inch more tight. It has never taken more than a 2nd time to stop them from coming loose . I always place 3 spent cartridges in the cylinder first so I'm not putting pressure on the alignment pins on the back face of the cylinder .