Now that more Omer "Airbalete" spearguns are in use I am wondering how the rotating muzzle covers are faring in terms of resisting grit contamination. I have found that large diameter (e.g. body tube size) rotating collars can pick up grit and score the underlying aluminium (or plastic surface) that they turn on because the particles can sit in the intervening gaps which are nearly flat (i.e. low curvature) compared to the grain sizes. This does not happen with collar diameters that have a much tighter arc (i.e. high curvature) like a spear shaft slider, where the grains are too big to fit into the curved gap unless they are very tiny in which case they are unlikely to bite into the metal and heavily score it, although they may jam the slider. Plastic collars also present the problem of grit particles embedding in the plastic surface and staying there, thus transforming the collar into a sanding tool which carves away a bit more metal or plastic with every twist. This is a difficult problem to engineer out, particularly if the underlying bearing surface is aluminum or plastic rather than steel, however if the gun never encounters the bottom then sand or other grit particles are unlikely to get into the muzzle area. Invariably a loaded pneumatic gun, which sinks, gets dropped sooner or later if you shore dive and at times get rolled around in the wave zone. Although the best intentions are to load the gun after crossing the wave zone on the way out and discharge the gun before exiting on the way back, it does not always work out that way, particularly when conditions change for the worse during the dive. Guns can also be laid down up on the beach where sand can be flicked or blown onto them on a windy day, almost guaranteeing that particles will reach places where you would rather that they did not go, but usually there are no gaps which cannot easily be rinsed out or which involve larger grain sized clearances between sliding or revolving items.
So how are these rotating muzzle port collars performing, assuming that users are even bothering to close them at all? Can they become loose or are they sprung-loaded to maintain tension on the revolving element even if some wear occurs?
So how are these rotating muzzle port collars performing, assuming that users are even bothering to close them at all? Can they become loose or are they sprung-loaded to maintain tension on the revolving element even if some wear occurs?
