Tomba - All in One barrel sealing

popgun pete said:

What you are really talking about is the shaft bowing and thus slightly changing approach angles as it passes through the muzzle restriction imposed by the stop ring and slider. Now everything is much clearer as muzzle loading the shaft when not parallel to the muzzle is a completely different problem and can result in bending the spears and maybe damaging the gun, something that beginners are capable of doing when their attention is not focused properly on the task.

On a standard wet barrel gun the stop ring and slider are not pulled tightly back into the muzzle, they can rock and move forwards if the shaft bows and changes its angle while entering the muzzle, plus there is a small amount of lateral play in the seating recess, whereas in the Tomba system they are held back in their seating recess, so they cannot tilt or move to accommodate the change. I had not thought of that being a problem, but now you have a clever solution to it and a vacuum indicator as well which is very good, in fact with a discernable travel distance it would be a very good indicator if you could detect the change in position by just looking at the muzzle.

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Crustyfish said:

Hi Tromic

I've recently come over to the dark side as I needed a gun small enough to take on a motorcycle camping trip, and bought a Seac Caccia HF 90cm. The short story is that I love it as it's so easy to dive with and I've taken a pile of fish, so it does seem to work. My question is if you make a dry barrel kit for this gun that uses the standard 7mm stainless spear? After reading this thread it sounds like these kits make a worthwhile difference to pneumatic guns so I'm very keen to try it out.

Carl

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popgun pete said:

If you want an escape path for trapped water in excess of muzzle capacity at initial loading then why not return to the covered relief port idea? You only need one port in a groove encircling the muzzle at mid-body and this groove filled with an external "O" ring or a rubber ring of rectangular section that lies flat over the port. In the "Salvimar" and "Taimen" systems (and some others using a special seal with a lipped edge rubber nozzle) the vacuum seal can momentarily open outwards with excess pressure to prevent a hydraulic lock, but an "O" ring cannot do this at the muzzle entrance or the vacuum seal will be broken and water may rush in during the remaining loading action.

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