• Welcome to the DeeperBlue.com Forums, the largest online community dedicated to Freediving, Scuba Diving and Spearfishing. To gain full access to the DeeperBlue.com Forums you must register for a free account. As a registered member you will be able to:

    • Join over 44,280+ fellow diving enthusiasts from around the world on this forum
    • Participate in and browse from over 516,210+ posts.
    • Communicate privately with other divers from around the world.
    • Post your own photos or view from 7,441+ user submitted images.
    • All this and much more...

    You can gain access to all this absolutely free when you register for an account, so sign up today!

Custom Made 110cm Pneumatic,a possible 33 feet gun.

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.


Mr. Long Post
Apr 22, 2002
All of you power hungry spearos,

It is a amazing that this forum actualy has plenty of non-active readers, I mean read only viewers. When I posted the thread of a possible recoiless & powerful speargun, I was expecting some brilliant guy to come up with an idea that might actualy made it possible. Thanks to Deeper Blue, a gentlemen contacted me on the recoiless speargun subject. The guy happened to be living in my back yard...... my country and in my city. Internet forum is a wonderful tool indeed.

After a few phone call, we decided to meet at my house. The gun is a pneumatic.................my old time favourite. The gentlemen built himself what can be the world most powerful pneumatic. Since I been a pneumatic guy in the past, I sure would like to see how this 110cm custom made one perform.

The gentlemen has been conducting test on it and in order to do accelerated damage test, the gun has been fired on land, out of the water for like 200 shots. Anybody who has used pneumatic and had the chance to dismantle one will know that death will come to the gun if shots are made not in water. The piston and the dampening system will collapse in no time.

So he came last week and I wanted to see the power it can deliver and to see that it won't explode if fired out of the water. I prepared as seen on the photo a solid teak block of 3" ( 7.5cm ) thickness, 5 layers of 6mm ( 1/4" ) plywood and a concrete wall behind all these. The 8mm shaft used has a unique adaptor to install a disposable 7mm diameter shaft of almost 40cm ( 16") long.

The shot was made, I never expected it will penetrate all the way, I think 3" ( 7.5cm ) in to my concrete wall after all the wooden barrier I used. Solid teak is not a soft material, plywood is sure soft. Untill now the disposable shaft is still stuck in my house wall......... I can't remove it !!!

The gentlemen have conducted a test in the water and he attached a 10 meter/33 feet shooting line of 80kg/176 pounds to the shaft. When the shot was made, the shaft snapped the shooting line and the shaft continued its flight for a little more distance........... it was lost. The water visibility was garbage and he was shooting into the deeper drop off part of the reef.

At a measured weight of 600 grams ( +- 1.2 pounds ) of shaft weight including a spearhead, to propel this shaft for 10 meters and still able to snap an 80 kg line, amazing amount of power was produced by the gun.

The way the shaft penetrated my wall, I am not surprised that this is a possible "10 meter effective gun".

The secret lies in the way this gun is loaded and how the inner barrel is designed. I must say this gentlemen is a brilliant person. Any pneumatic gun designer will point out that at the power level I am describing can be achieved but no way to load the gun. In simple English, I am talking of an equivalent of 1,500 psi of loading force. You may fart to death, you still can't load a gun with this kind of pressure. I can't tell how he did it because he wants to keep it lay-low for a while. I am looking at a 110cm gun, all stainless steel and weights +- 2 kg and has a power equivalent to about 8 x 9/16 rubbers.

If you want to see the photo of the "stuck" shaft with a size reference, look at my beautiful toes on the first photo, lower right corner. :eek:

Since pneumatic push a shaft from its ass, we all know that this is the best and most accurate method there is to launch a shaft, a further R&D might be able to make this gun the shortest, lightest slimmest, easy swing, one hand shot, almost recoiless "Tuna" gun in the world.

I advice him to try an 11 mm shaft diameter because of the power potential of this gun. This gun will later be designed to accept 8mm and 11mm shaft with a special muzzle adaptor.
He is back to the drawing board to make a mid handle version. I will probably advice him to make one that mount on a shoulder like shooting a big bore rifle, this way he can install an aiming/sighting system that allows sniper style shooting since there is almost no recoil to break shoulder bones.

Why do you think boys, a 110cm speargun that shoot as far away as a 170cm+ Steve Alexander ?

The gun is still crude lookin cause its a proto type. Photo next time.

Damn ................ if Jay Riffe ever put his machining expertise on this baby, it sure will look space age.

More Photos....

For those who wants to see the concrete wall penetration in greater details, see top photo.

Lower photo:
The solid thick teak wood split open from the penetration of the 7mm disposable front shaft. If if weren't for the 10mm special adaptor on the shaft to accomodate the 7mm shaft, the penetration should be better.
Don't surpose you could attach a picture of this weapon by chance could you? Or give the name or nick of the designer as he is found on this web page? *grins*
What type of antirecoil mechanism is he using? for a weapon of those dimensions with that sort momentum there has to be quiet a lot of back pressure... There isn't a lot of ways i can think of to diffuse that kind of backpressure whilst underwater... Mind you no one believed a bomb as big as a nuke could be possible once upon a time... now we got H bombs Neutrino rays and bombs that just fizzle instead of going bang (bye bye DNA)...
Look forwards to a pic of this speargun (or mortar) :D
Wooooooooohoooo !!!

Sheez .... I couldn't drive that spike into the wall that far with a SLEDGE HAMMER .... dang, that must be one brute of a puppy .... show and tell !
Ok My Dearest-s,

I'll call him again and will post some picture. He rather remains a mystery man. Let's call him Mr. Pneumatic, he reads this forum often anyway.

OK, this gun does not have much recoil because it is a pneumatic, pneumatic is more efficient than any band/rubber gun, length for length. I will say the recoil equivalent at the most is like 2 x 16mm band gun.

Band gun do have greater recoil because the mass of the rubbers collided with the muzzle during a firing, since the rubbers do have mass and "snappy" it contribute some to recoil and thick shaft also add more recoil.......so they say..........and I tested.........it's true.

For the pneumatic, it is more efficient because the entire length of the barrel is the length of the propulsion area, as for rubber, 1/3 of total barrel length already wasted for the rubber length itself in "rested" state. Thus same length pneu and rubber gun will yield better power for the pneu if we based on say on 3 x 14mm or 255 pounds of pressure in a band gun to be compared. A typical pneu energy storage is 300 psi in un cocked state, in a cocked/loaded state add something like extra 15%. Since the average piston diameter of a pneumatic is 11-13mm round, a 300 psi of air pressure can not be converted directly to pounds of equivalent rubber pressure because 11-13 mm diameter is too small ..........not even 1 square inch.

In say a 255 pounds pneu, a shaft get propelled a 100 % of the barrel length, as for rubber gun, the last 1/3 of the shaft travel get no more energy from the band, this is why Steve Alexander noted that ( Matrix Open your Bluewater Hunting book page page 64, line 5 from start of page ) extra muzzle length after the rubber slot is no good.

The problem with pneu is that very few people can load a long one cause a 100 cm gun need 200 cm loading length. A hard to load pneu is dangerous cause your leg will slip and accident can occur while loading.

So the recoil that contribute to a pneu is only the mass of the shaft, as for the piston driving the shaft, the mass is very small and thus less recoil in this department. Other factor in pneu is that since they all use double barrel configuration, energy propelled to the shaft is more "evenly" per inch/cm of piston travel, hence per inch of shaft travel too. Double barrel in pneu means that the firing barrel is the small one where u insert ur shaft, the outer barrel is the main barrel that enclosed the firing barrel and act as the main air reservoir. Both barrels has air reservoir capability.

As for band guns the power ratio is equivalent to amount of stretch of the rubber. Say my Riffe #2 is 20" (51cm ) rubber length. We divide by two to get a stretch reading. When loaded it get elongated to 32" ( 81CM ) per side at 320% Riffe standard stretch setting. At this 320% stretch, we get 85 pound of pressure per rubber, so 3 rubbers put me at 255 pounds. I fired, the moment the shaft left the trigger, I am getting a 255 pounds of calculated/theoretical recoil multiplied by the shaft weight and bla bla bla but the rubber energy ends by the time the shaft butt has travellled only 22" (56 cm) down the track/barrel. So an "X" amount of energy was spent on this gun for a mere 56 cm of travel and by then the rubber has zero energy.

In plain language :
if I were allowed to pay a bill of 255 pound ( British Pounds :D ) in 56 days ( cm of travel ) ,I get more shock ( recoil ) than if I were allowed to pay 300 pounds in 95 days. :friday

For the pneu gun, even in a non-loaded situation, the air inside the barrel is already compressed, there is a stored energy at all times. The moment a 110 cm pneu is fired, the shaft is being pushed by the total compressed air plus the extra compressed air of the small firing barrel. Since a 110cm, has an estimated of at least 95 cm of effective barrel length ( the rest for the butt and bla-bla-bla ), this shaft gets pushed all the way in the barrel, evenly and nicely............... untill it left the barrel. The moment the shaft left the barrel, the amount of energy in the gun is not zero, it still in a compressed state as it is.

In a simple comparison, say this pneu shaft gets ......say 255 pounds of pressure the moment the trigger released it, but all the way down the barrel till it exited out, there is like at least still 200 pounds of energy remaining when the piston hit the muzzle stop.

The calculation method is definitely wrong but the numbers I am trying to interpret should be like this :

3 Band Gun, Say Riffe #2
255 pounds of power is linearly reduced to zero pounds in 56 cm of shaft travel. Another travel of 40 cm to the muzzle end is from the momentum and therefore must be reduced by water hydrodynamic resistance and track resistance of the barrel/track. So the power available pushing the shaft is as follows :

First 1 cm of travel = 255 pounds
After 2 cm of travel = 245 pounds
After 3 cm of travle = 241 "
After 4 cm of travel = 236 " and so on and so on till it become zero at the last 56 cm of travel.

A pneu shaft gets 255 pounds of energy for the first 1 cm of shaft travel, since it will still retain 220 pounds of pressure after traveling for 95 cm..........Damn !!!!! The total available energy efficiently harvested by the shaft is so massive. :crutch

I hope I am right. Ok boys, I will update you curious souls every now and then. I want to test it in water soon.

Stay Dreaming......
OK, Mr. Pneumatic's friend ....

What efeect does the increase in pressure (with depth) have on a pneumatic gun? I've been told that it's quite negative, I have no experience with Pneu guns whatsoever. Just a curious question - what would the difference be between the pressure at 0m and -10m, then -30m etc.

After all, a gun that you can't shoot below -30m is not a REAL gun .... :D
Good question SASpearo

This is the same question/fact I wanted to test personaly. I had pneu a long time a go and at 30meters they were quite poor because there is already 4 ATM/60 psi of efficiency lost due to the water pressure.

Will let you know in a few weeks if I get to test it, but the designer is aware of the limitation of a pneu. In my estimation if it say loose 2 m range at 30M, 8M effective is still deadly for a 110cm gun.

BTW, I remember that you wanted me to post my Riffes photo to let you know how I rig it. Attached 2 for ur viewing pleasure.

Top photo :
From bottom to top items. 7mm x 50" Hawaiian Shaft, 2 wraps shooting line 400 lbs black mono - a Virgin !! 8mm x 50" Hawaiian Shaft, 3 wraps 400 lbs black mono. 8mm x 48" Threaded with Ice Pick, 3 wraps 500 lbs coated stainless steel cable. Riffe Standard #2 Mid-Range, rear handle. 4 x 9/16 bands, muzzle re-inforced. I have another NOT SHOWN, a 3/8 ( 9.5mm ) x 48" threaded with Ice Pick and 2 wraps of 500 lbs coated stainless steel shooting cable, I hate this shaft on long dive, muzzle heavy.

Riffe Standard #4 BAJA, rear handle ( 30% thicker teak stock than #2 ). This is a rear handle equivalent length to a Riffe Mid-Handle Island which our Sultan Sven has. Stablizer Wing kit, 3/8 x 60" shaft with Ice Pick. I added an optional rest tab ( see lower photo ) cause it save me energy loading the 4 x 5/8 rubbers. Also using 3 wraps ( 9 meters ) , some may call it 6 wraps, 500 lbs coated s.s cable. I have a spare 8mm and 7mm shaft for the #4 to test but no time yet. So many "want-to-do" list but not enough time. With 4 bands this is a deadly 6 meter gun, I am very conservative at estimating shooting range. Very mild recoil even with 3 bands and 9.5mm heavy shaft on a single hand hold. I'm sure it shoots like a dream using 8mm shaft with 3 bands, will test and let u know. Surprisingly well balanced even with 3/8 (9.5mm ) shaft, I expect it to be muzzle heavy. The Muzzle Wing Kit also works ( this answer to Chief Anderson question ).

The #4 at 155 cm is about the longest I will go for any gun, short me can't handle anything longer. This is my own version of blue water gun. Maybe next time I add my own modification to this one but for now, the water visibility and my usual hunting area does not permit me to use this mini cannon.....yet.:head

I have a Riffe float with 100' and another 50' of float line. I use Riffe breakaway assy and I add my own extension line, a 1,000 lbs double crimped Kevlar so that I can use my existing shooting line instead of dedicated break away shaft/line arrangement.

Damn.......where are the fishes when I am all set to hunt ???:(



Your setup looks pretty comprehensive! There's some tunny out there with the 9.5mils name all over it.

Just a quick question, and please pardon my ignorance. you mentioned that a standard pneu has about 300psi, uncocked! and then you ram the spear in, creating further pressure, am i right? how is the outer barrel pressurized? do you use scuba or one hellva lot of pumping on the surface? it seems like a lot of effort. is it? and what about the monster that you friend has created? for the amount of power that it puts out, it seems like you'll need to be followed by the ship that carries the compressor!

all (positive) input is greatly appreciated

Hi Griff,

Long time no hear u. Many people who never use pneumatic thinks one must pump air to shoot everytime. This is not the case. Pneumatic gun is very similiar design as a car shock absorber, you don't loose air for every shot ( unless there is a seal leak of course ). The air stays in the small and bigger barrel all the time. It uses the rebound effect of compressed air to drive the air tight piston and hence the shaft. It is not like the scarry M-16 Look-Alike compressed air gun I recently posted where the power source is compressed air and the air is wasted down the barrel for every shot.

If you never load a pneumatic, say a 95cm Mares Cyrano, it sure need practice to do it. After a while it is easy. In fact when I threw away all the pneu and went for a JBL Aluminum Magnum, I THOUGHT the 12mm original black rubber was tough to load and thus it must be a very "Macho' gun phewwwww :blackeye , what a dummy I was. After some practice, it is easy. Now I can load 2 of 12mm Riffe rubber (1 year old of course ) on one go for a Competitor #1.

Try a Mares Cyrano, a 95 cm is fun size and the accuracy is amazing. Sometime I feel like getting one for memory/fun sake but it ain't so cheap at +- US$265.00 here. This is the best gun for fast Rainbow Runnners, not deeper than 90 feet gun though. A very nice cave/hole gun too. You can mount a torch called the Underwater Kinetic Mini Q40 on the barrel side ( i'll teach u how ) and you can shoot where the light shine like a laser dot. Great for grouper lurking in dark holes/caves.

Stay away from the Great White,
not exactly

Sorry guys
Can't resist calling someone on another apples/oranges comparison.

First 1 cm of travel = 255 poundsAfter 2 cm of travel = 245 poundsAfter 3 cm of travle = 241 "After 4 cm of travel = 236 " and so on and so on till it become zero at the last56 cm of travel.A pneu shaft gets 255 pounds of energy for the first 1 cm of shaft travel, sinceit will still retain 220 pounds of pressure after traveling for 95 cm ..........Damn!!!! The total available energy efficiently harvested by the shaft is so massive.

The way I look at it for a 50" gun;

stretched rubbers (easy Sven) 32"
relaxed rubbers 10"
average pull (est.) 125#
available energy 125x22/12 230 foot pounds

est length of piston travel 40"
average push 75# with 300 psi and a 13 cm piston
available energy 75x40/12 250 ft lb minus 10% at 66 ft

If you use longer and heavier rubber, the figures swing more in rubber's favor. 300 psi runs into two or three limits. It sure is fun recalling the tests we did. I liked the spring guns best but.......
  • Like
Reactions: icarus pacific
Aloha Bill,

OK OK, you win Bill:D :D . I do love my rubber guns anyway.
Since you are from Hawaii, may you feed me with info please.
The Wong guns..... how good are they ? I see on video that the trigger sear and trigger is made of some high tech polymer/plastic, I feel scarry of plastic....u have any personal experience with them guns ?

My mouth do water a bit looking at the Wongs. I drool on all nice guns I do not yet own anyway.

Hi, every body.
I am looking for photo and instruction to dismantle a Mares miniministen, when i've found your forum on the web.
my gun is leaking oil and do not keep the pressure in.

Can please anyone help???
thank you
change the o-rings and apply the proper silicone grease, or alternatively, go to your nearest Mares dealer or speargun shop
You don't have to give away secrets but speculation would make me think that maybe there could be a small pony bottle attached somewhere?
I saw another gun in a video , The guys name was Marc something and he was spearing around Rigs in Africa , he had a pony bottle setup screwed on to the back of the gun, and power seemed pretty impressive.
This solves the whole compressing-the-air with shaft loading problem.
One thing which may or may not apply/interest you, If applying for a record you have to use a self cocked gun.
Anyway next time shoot the spear into the wall a little higher and use it for a flagpole.
Nice pics
very interesting indeed, I have always thought that air gun where impresice and that they failed easely. Now I am thinking about buing one for bad viz. Also very interesting for blue water a 140 cm euro gun is pretty hard to fit in a plaine
pope said:
Hi, every body.
I am looking for photo and instruction to dismantle a Mares miniministen, when i've found your forum on the web.
my gun is leaking oil and do not keep the pressure in.

Can please anyone help???
thank you

You should look at this


So when can i buy one?? :) :) :) :)

My biggest worry is carry a loaded 4 or 5 band blue water cannon on the boat. The general rule is UNLOAD all guns before you get into the boat, but with those tuna, alot of the times your best shot is when you just get into the water. I've had a 90kg YF eating chum, less than 1m from my fins, whilst i'm busy loading my gun!!!!! Super-duper-pneumo-gun would be PERFECT!!!!

Ermmmmm, i will happily supply my services for testing that gun on some big fishies!!!!! :p :p :p


The Guy that you mentioned in Africa is A french Spearo, Marc Antoine Berry, that fishes in Gabon offshore rigs.
He uses a Pelletier Speargun (French Speargun) this is a comercial speargun, that like you said, uses a pony bottle. You do not have to load the spear into the gun like in the other pneumatic guns, just put the shaft inside and them screw the bottle.
This is a very old design and illegal in most of the countries just like the CO2 spearguns.


By the way Marc Antoine Berry now use another gun, a wood one. the system is quite simple, he is using a roller gun, bands are attached under the barrel near the handle and go trought a pulley on the muzzle then to the fins...wishbones are made of dyneema...
DeeperBlue.com - The Worlds Largest Community Dedicated To Freediving, Scuba Diving and Spearfishing


ISSN 1469-865X | Copyright © 1996 - 2024 deeperblue.net limited.

DeeperBlue.com is the World's Largest Community dedicated to Freediving, Scuba Diving, Ocean Advocacy and Diving Travel.

We've been dedicated to bringing you the freshest news, features and discussions from around the underwater world since 1996.