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Dirty water ruining orings?

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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Jan 21, 2020
Does anyone know if it's likely dirty water will ruin the o ring on the piston? This year it seems the water has been very dirty so im curious to know if that's whats causing it, i swapped out all the o rings and on my 2nd shot the piston jammed up again about 5 inches down the muzzle, in true brute fashion i forced it, whenever the piston was at the tip it leaked. I have some light looking scratches inside so i ordered another barrel just in case, any thoughts?
For the piston to jam you must have foreign material in the barrel that has got between the piston body and the inner barrel surface. That effectively wedges the piston and forcing it will scratch the inner barrel. Once scratches are more than faint lines with no depth then the gun will leak air as the rubber sealing surface cannot extrude into the longitudinal groove created. When that happens you need a new inner barrel. The rubber seals as such don't damage with grit, but running on the damaged barrel will adversely affect them although as the piston can revolve as it is forced down the barrel during loading the grooves are not always running on the same parts of the seal periphery. In dirty water after loading the gun you should hold the gun muzzle down and shake the gun to allow any foreign particles to move towards the muzzle. They will then be blown out with the next shot. Vacuum barrel guns are less affected as loading does not suck water into the barrel if the vacuum cuff is doing its job. In Russia and Ukraine spearfishing is often carried out in turbid river or lake water with suspension of particles and hence guns use stainless steel inner barrels to better cope with such conditions, however these are not really needed in marine conditions as being able to see determines if you can shoot anything at a distance.
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Note my comments above are for when everything is wet, sand in a dry gun is more destructive as there is a lack of lubrication which would otherwise allow things to slip rather than bite into surfaces. You don’t want sand in a pneumatic gun, so they need to be rinsed off by swishing them around in water before introducing a spear if the gun has say been laying on the beach, especially on a breezy day where sand grains can be blown around and into the gun.
I see, i ordered the new barrel so hopefully that fixes everything. ill be more attentive of foreign particulates as well, thanks for the feedback
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