"Vacuum Barrels" aka "Dry Barrels"

[Mark Lamont]

Reading your reply, It made me laugh. I think that anyone that has had a slider hang up part way down the shaft knows just how squirely a shaft can fly out of a gun. I witnessed Jimmy D cock a long gun out of the water with the exact same result while diving kelp paddies. It scared us all so bad we wanted to kill him. It really is not funny until years later. Safety comes first. Jack Pradanovich lost an eye to testing in the pool and that was never funny.
I have used my cocking device for many years and feel very safe with it. It was posted today somewhere in the pneumatic section with photos.

 

[foxfish]

I had a close miss with an airgun, I wrote about it here http://forums.deeperblue.com/beach-bar/85751-like-tears-rain-2.html

 

[Gizzo]

Dear friends, sorry if I probably lose some details in your discussion because english is not my mother language. I am a staff member in an Italian hunting forum (where there is continuos discussion on this topic) and I have used pneumatic guns since 1970, this means only that I have developed my personal opinion on wet and dry barrels and want share with you. I have used Mamba 110 and a x-power system, and my conclusion was to save money and never buy them. I love new technologies but I think that some simple modifications on your own speargun are enough to give you very good performance without arriving to the vacuum systems.
Some more: Mamba system in my opinion is the worst, because adds too many objects to the arrow that must be as more "aerodinamic" as possible. The other systems that put the line on the top of the arrow are better, but if you try a normal Cyrano with the best tuning (low density oil, tahitiana, 30 bars, etc..) you will hardly feel / or see any difference. I use the line on the top of the arrow on a short (70cm) wet speargun when I go in turbid waters, I do not use such system with the long speargun.
Again I want to say these are my personal opinions.

 

[tromic]

Dear friends, sorry if I probably lose some details in your discussion because english is not my mother language. I am a staff member in an Italian hunting forum (where there is continuos discussion on this topic) and I have used pneumatic guns since 1970, this means only that I have developed my personal opinion on wet and dry barrels and want share with you. I have used Mamba 110 and a x-power system, and my conclusion was to save money and never buy them. I love new technologies but I think that some simple modifications on your own speargun are enough to give you very good performance without arriving to the vacuum systems.
Some more: Mamba system in my opinion is the worst, because adds too many objects to the arrow that must be as more "aerodinamic" as possible. The other systems that put the line on the top of the arrow are better, but if you try a normal Cyrano with the best tuning (low density oil, tahitiana, 30 bars, etc..) you will hardly feel / or see any difference. I use the line on the top of the arrow on a short (70cm) wet speargun when I go in turbid waters, I do not use such system with the long speargun.
Again I want to say these are my personal opinions.

Gizzo, here is one difference worth of converting wet barrel to vacuum barrel. Instead of having your Cyrano on 30 bars you could have it on 24 bars and will have same performance and much less noise and lower recoil. Deeper you go, the performance of the vacuum barrel is still better compared to the wet barrel. I agree about all other you said.

 

[Gizzo]

Tromic I will consider these elements :"less noise and lower recoil" and will discuss with those in Italy using it. About the 24 instead of 30 bars it doesn't matter with 11mm barrell, I think. Have you never used Mares Mirage? I have it and is the top.

 

[tromic]

Tromic I will consider these elements :"less noise and lower recoil" and will discuss with those in Italy using it. About the 24 instead of 30 bars it doesn't matter with 11mm barrell, I think. Have you never used Mares Mirage? I have it and is the top.

It is 6 kg less loading effort. I would like if I had a Mares Mirage. It was very interesting gun.

 

[Gizzo]

In Italy is still possible to find a Mirage but the price are quite high, about 350 euros.

 

[tromic]

In Italy is still possible to find a Mirage but the price are quite high, about 350 euros.

Thanks, Gizzo! Good to know, but now I am quite happy with my Cyrano-Tomba.:friday

 

[Gizzo]

Cyrano is one of the best modern spearguns, but I do not understand what is TOMBA. I know with that name a famous Italian Sky Champion and our final house in the cemetery.

 

[tromic]

Cyrano is one of the best modern spearguns, but I do not understand what is TOMBA. I know with that name a famous Italian Sky Champion and our final house in the cemetery.

I agree with you that Cyrano is one of the best modern spearguns especially for use in the sea. Tomba is the name for the vacuum barrel system for pneumatic spearguns I have been working on for last 2 years.
http://forums.deeperblue.com/pneumatic-spearguns/81791-tomba-all-one-barrel-sealing-16.html

 

[Gizzo]

I have seen, thanks.

 

[popgun pete]

As vacuum barrel pneumatic spearguns have the potential to hold saltwater in the annular space between the front piston seal and the front of the piston when it presses on the shock absorber anvil (or stopper) this small volume area needs to be washed out in order to avoid corrosion. Refer to thread http://forums.deeperblue.com/pneumatic-spearguns/91611-corrosion-potential-vacuum-barrel-guns.html

Hence before long term storage of the gun the piston should be pushed back with the muzzle pointed downwards in order to allow any water droplets in the inner muzzle to drain out. If the gun is depressurized then the piston will stay retracted and the interior of the muzzle will completely dry out, otherwise it would be worthwhile to flush out the muzzle with freshwater as its presence is unlikely to cause corrosion, whereas saltwater in continual contact with the front end of the alloy barrel will damage it. Plastic pistons make this less of a problem than it would be for those guns with metal pistons where there is a slow galvanic reaction between dissimilar metals if saltwater is continually present.

 

[tromic]

These pictures I found on a Russian forum. Just suits here nicely!

 

[slopshot]

Where can a "dry system" be bought?

 

[slopshot]

Where can i get a "dry system"?

 

[popgun pete]

Where can i get a "dry system"?

Read this thread, mainly the latter pages as it is a very long one.
http://forums.deeperblue.com/pneumatic-spearguns/81791-tomba-all-one-barrel-sealing.html

 

[popgun pete]

As vacuum barrel pneumatic spearguns have the potential to hold saltwater in the annular space between the front piston seal and the front of the piston when it presses on the shock absorber anvil (or stopper) this small volume area needs to be washed out in order to avoid corrosion. Refer to thread http://forums.deeperblue.com/pneumatic-spearguns/91611-corrosion-potential-vacuum-barrel-guns.html

Hence before long term storage of the gun the piston should be pushed back with the muzzle pointed downwards in order to allow any water droplets in the inner muzzle to drain out. If the gun is depressurized then the piston will stay retracted and the interior of the muzzle will completely dry out, otherwise it would be worthwhile to flush out the muzzle with freshwater as its presence is unlikely to cause corrosion, whereas saltwater in continual contact with the front end of the alloy barrel will damage it. Plastic pistons make this less of a problem than it would be for those guns with metal pistons where there is a slow galvanic reaction between dissimilar metals if saltwater is continually present.

A gadget to do this cleaning is described here: http://forums.deeperblue.com/pneumatic-spearguns/97710-cleaning-vacuum-muzzle-guns.html