hi all, long time reader infrequent poster!. Got into spearfishing last summer and love it. I am an aircraft engineer by trade with access to a range of manufacturing machinery so i thought i'd have a go at a bit of diy speargun making. one thing that puzzles me though, on an open muzzle design gun what keeps the front of the spear in the rail whilst tracking through the water? surely the water pressure/drag would displace it? any input would be greatfuly recieved!