i heard it acts as a gas seal and alot of times improves accuracy......and if your bullets tumble and hit sideways i heard they fix that......i shoot maxihunters in my tc 50cal hawken flinter....and dont use them...couldnt find them so i shot without them.....and it shots fine for me.....ill use them next year or late season when i find them...i saw them a few weeks ago....so ill pick them up.....sure they will improve my groups......or maybe ill goto patch n ball for the late season.....i get some awesome groups with them....ill see what happens...you got me thinkin now!