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One Air Firing Issue

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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Well-Known Member
Dec 5, 2005
I'm having an intermittent issue thats just started when firing my one air 70.
When I fire it the trigger releases, the line release works but the shaft only moves around 10mm then stops. I can re cock it and it will then fire fine. It then is OK for a number of test shots but as soon as it has been loaded for some time and I try to shoot a fish it has the above issue.
I'm going to have a look this week and wonder if anyone has any thoughts on what's going on? I'm guessing it's a problem with corrosion on the sear or piston tail but tbh I'm a bit stumped by it.
Here's a wee clip of the issue.
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Reactions: Zahar
I watched your video and I see the line releases, but the gun does not fire. On that family of guns there is a peg on the trigger that secures the inner end of the line release, so when it tips down the line release is free. Most likely the adjustment on the long sliding rod that the trigger pushes on is out. You adjust this by screwing in the grub screw in the rear of the handle. Do it with the handle removed to check how far the rod projects forwards gradually increasing it until you get it working properly. Wear on the parts can make adjustments go out over time, this is mentioned in the gun's handbook.
trigger adjustment OMER ONE AIR.jpg
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Thanks Pete, that makes sense. I'll have a look at that this evening.


Here is how far the pin moves inside the gun when it shoots, going from safe to fire with the trigger pulled.
safe and fire One Air R.jpg
The shaft only moving 10mm and stopping would not be explained by this trigger adjustment, but that was not shown on the video, unless I missed it. The piston jamming seems unlikely if the gun shoots OK later. The fact that it occurs with the gun loaded for a longer period may indicate that the inner barrel is filling up with water. Although that would hydraulically lock the piston, a water leak in the muzzle seal would allow the shaft out at a reduced velocity. Unlike the vacuum seals on other guns the one used here is not a nozzle type that can blow open with pressure behind it, so it is possible that it might hold everything back. Hydrostatic pressure could then blow the spear tail out of the piston if it was not jammed in tight.

If the latter is happening then you may find some seawater inside the gun.
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