• 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!


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.

Nice to dream , but i think the day someone gets all this frankencannon harpoon stuff right, the authorities will ban spearfishing.

As it is its a minimalist sport. No scuba, restricted species, restricted bag limit, no propulsion devices, blah blah. No way you are gonna be allowed to play rambo in the drink and blow away heaps of coral after sawing a whale in half.

Not to get technical

Just as an aside note, if you have a cyliner that can handle the 40-50,000psi or even 3,000psi that Murat is refering to, the less than 100psi from the outside isn't going to make abit of difference. There is a pistol that is made for shooting underwater for the SpecOps people. I believe it only has a range of 30 or so feet. The projectile actually fills the barrel and sticks out the end. Let us know how you progress SASpearo. Sounds like a cool idea that the military would buy if you perfected it. How about using depleted uranium for your bolt, it has tremendous weight for it's mass so you could go w/ sm diameter to help w/ the frontal surface area problem of a larger diameter shaft. I think the noncompressability of water is going to win in the end, but it's fun trying.:duh
more than a screw loose...

Originally posted by Jay Styron
How about using depleted uranium for your bolt.

Yeah. That'll help that length problem. You'll have fun with the glow-in-the-dark feature too.

Re: more than a screw loose...

Originally posted by icarus pacific

You'll have fun with the glow-in-the-dark feature too.

does she have problems finding it?:D
To Iya and sundry tech freaks .;)
Here's a quote from Granny Weatherwax , a lady I admire greatly :

"Progress just means bad things happen faster ":D
Amen , Skin
Muhahahahahaha:D :D :D

This thread become freak rofl

I am wondering if any of you guys imagine what wil happen when you use uranium in water?????

Uranium generally using in nuclear bombs and chemical reactions.

It has half life. I mean it will become useless after some period of time.
Originally posted by Murat
I mean it will become useless after some period of time.

Correct Methusalah , I mean Murat . In a couple of thousand years it will be no good .rofl
Wha ha ha ha, I am enjoying this:D :D

Let me join in the dreaming part..............


01. Fire arms bullets even they are small, they get stabilitity from the spinning, like a gyro effect. This is why the have rifling in the barrel, it spin the lead projectile. I am afraid too small a shaft/bolt will not have enough mass thru specific density ( must check depleted uranium rod density, do I need a full radiation suit ? :D ) to retain forward inertia for the say...10 meters potent shot ? Also having a 10 meter shooting line might be a massive drag to the light weight bolt in terms of water drag or extra weight to drag along, at least in percentage it doesn't look good, accuracy might suffer.

02. Red Roman + red wine on coal....YUMMY YUMMY :t

03. Using explosive/bullet as power source will not qualify ur catch for the world record, unless u only want the fish meat...sell the meat !!!

04. Using 3000psi scuba source compressed air is the most efficient method there is. If there is good engineering, the power potential of 3000 psi ( less some losses ) is yours, no rubber can match this. Almost no recoil, loud noise though, most powerful for the lightest possible gun, extreme accuracy from 100% barrel, need good machining skill and must make an efficient in line valve plus pneumatic trigger instead of impact hamerring type. But again I think can not do world record, unless you buy the special 3000 psi manual pump and pump urself the air reservoir (mini 3 shots tank probably, Spare Air size ) u are using. If u read the rule book.....your own loading effort is required, so there is a loop hole here. They did not state that u CAN'T pump the air today and use it tomorrow for the hunt:eek:. If you want this one just buy one, I already posted one existing model sometime ago. Modified a bit and she is all yours. Making one urself will be more fun though...........

05. SKINDIVER, can't you see we are having fun dreaming here ? Don't get too excited lad, we can always throw a stick of TNT on a feeding tuna if meat is all we are purely after.

06. I love the muzzle slide thing....let me dream of it. I am still trying to figure out how to make a RECOIL SCALE/REGISTER.

07. I am still puzzled too why the muzzle kick up. I thought the rubber hitting home on Riffe/Alexander type open muzzle, should make the gun point down, not up ? Let me borrow a friend U/W video and I try to record and view in slow motion like Steve did.

08. If one can make a 50,000 psi tank, I think a recoiless Frankegun will be a less expensive engineering because the compressor must be as big as my house. Murat, did you add an extra zero or what ? :D :D

09. OK I' done.

DEPLETED uranium

OK, lets read this together. DEPLETED uranium. Emphases on DEPLETED. Its the stuff the government uses in their armor pierceing rounds. And besides by the time you land your tuna it's already med. rare.
So .....

how about a spinning shaft? Should be possible - if you put wings on the back to stabilize the flight and make it spin - you can use the same wings for your wishbone - if you go with a wishbone ...

Mmmmm ...

Shooting line might be an issue - not a problem. Have a reel that freespools when the shot is fired, running the line through a guide, and making sure that the line is not creating any force besides deceleration - ie have it centered exactly in the middle of the shaft .... shoei ...

As for the WHY of Frankengun ... No, I'm not gonna tell ... what do you guys think it is being built for?

And who on God's blue earth is Granny Weatherwax? Is she related to my Aunt Earwax?
Aww SA , you literary philistine !;) , have you not delved into the collected wisdom of the great modern writer Terry Pratchet ?
Alas ...

I have not. I've delved into a great many authors, and have always threatened myself to take up Terry's books .... sigh.

So much time to read, so much fish to spear .... choices choices ...

New speargun? 100 books?
A-yup ....

There's two main ones ....


and http://www.freediver.net/iusa/

Sigh .... If I found a magic lamp (one with a genie in it) and got some form of wish, it would be that the world would stop bickering - all this 'double' entities for absolutely everything .... I mean, a record is a record, right? Be it Spearfishing or freediving or whatever .....
Thanks Boet , the reason I aked is that I saw a bus great barracuda today at a cleaning station while scubbering . It just sat ther for app. 10 mins. The record listed is 21.6 kg , if this fish was much under 30 kg . I'll swallow my spear .:D
The longer I stared at its jaws the less inclined I felt to spear it :eek:
Guess if I was hunting the spear would have been in before I had time to think of possible consequences . Having said that , wouldnt shoot a sitting target .
ah ... cleaning stations et all ...

Not my style - but ALWAYS tempting. I ran into a cleaning station off Leven point a while ago .... there were these grandmother Yellowbellie Rockcods finning in queue .... must have been all of 25 to 30 kg's .... tempting .... so tempting. I had to unload my gun and tie it to my float to fight the urge ... he he he.

When are you gonna make a turn in SA again? Bring yer rail, we go after some daddies at Kosi .... or down at Leven point ... I'm moving back to Jo'burg this weekend ... Will be closer to warm water than I've been in the last two years here in Cape Town (Skaapstad)
Maybe this should be a new thread

I was looking at the two sites that you gave the links for. dont they feel realy arb when they quote the record for something when its half the size of the other record

like this one
giant trevally- IUSA 35.8kg IBSRC 54.88kg

id feel an idiot if i was listed as the "world record" holder for the 35 kilo fish.

Spinning shaft is defintely not a do-able idea for underwater projectile. The projectile must be in a 100% fully enclosed barrel in order to spin, how are we going to propell the shaft and the shooting line attachment will not work. Also by the 1000s?? times more drag in water than air, introducing other movement to the shaft/projectile aside from going forward will be a waste of energy. The best will be to have fins on the shaft that can be set/designed as such, it has a correction effect of an airplane airleron/flaps ( spelling ??? ). This way we can counter the going-to-low shoots effect by gravity for a specified distance.........say 10 meters effective. So we have a flat shooting gun...in theory.. I wish.

Jay deplete Uranium rod might be a good idea if u want the one of the heaviest metal there is on earth, I think the price and getting it might be a problem. Imagine a 6mm shaft so stiff and so heavy like a 11mm .........must check the DU specific gravity, here is the list. I just surf this especially for you dude .......

Aluminum, cast-hammered 2.55 - 2.80
Brass, cast-rolled 8.4 - 8.7
Bronze, aluminum 7.7
Bronze, 7.9 - 14% Sn 7.4 - 8.9
Bronze, phosphor 8.88
Copper, cast-rolled 8.8 - 8.95
Copper ore, pyrites 4.1 - 4.3
German silver 8.58
Gold, cast-hammered 19.25 - 19.35
Gold coin (U.S.) 17.18 - 17.2
Iridium 21.78 - 22.42 ================ 1st
Iron, gray cast 7.03 - 7.13
Iron, cast, pig 7.2
Iron, wrought 7.6 - 7.9
Iron, spiegeleisen 7.5
Iron, ferrosilicon 6.7-7.3
Iron ore, hematite 5.2
Iron, ore, limonite 3.6 - 4.0
Iron ore, magnetite 4.9 - 5.2
Iron slag 2.5 - 3.0
Lead 11.34
Lead ore, galena 7.3 - 7.6
Manganese 7.42
Manganese ore, pyrolusite 3.7 - 4.6
Mercury 13.546
Monel metal, rolled 8.97
Nickel 8.9
Platinum, cast-hammered 21.5 ============= 2nd
Silver, cast-hammered 10.4 - 10.6
Steel, cold-drawn 7.83
Steel, machine 7.80
Steel, tool 7.70 - 7.73
Tin, cast-hammered 7.2 - 7.5
Tin ore, cassiterite 6.4 - 7.0
Tin, 100% Pure 7.29
90 Sn & 10 Pb 7.54
63 Sn & 37 Pb 8.42
60 Sn & 40 Pb 8.52
50 Sn & 50 Pb 8.89
10 Sn & 90 Pb 10.50
5 Sn & 95 Pb 11.00
Tungsten 19.22 ============== 3rd
Uranium 18.7 ================ 4th
Zinc, cast-rolled 6.9 - 7.2
Zinc, ore, blende 3.9-4.2


Try this engineering link :

Here is some idea of the contents :
* I am still trying to find if any info which is good for recoil absorbers, too much too read.*

Structural Damping Techniques

Significant progress is also being made in the development of novel structural damping techniques that could have a significant effect on how helicopter rotor blades and weapons systems are designed. New schemes currently under investigation include magneto-rheological and electro-rheological fluid based damping devices, active constrained layer damping treatments, piezoceramic actuators bonded to a structure and coupled to a shunted electric circuit, and nonlinear controller facilitated energy dissipation through an electronic circuit. Other new approaches, such as distributed control techniques (in contrast to controllers for discrete systems), localization and isolation of modal response, delayed action vibration absorbers, and neuromuscular-like control for absorbing structural vibration energy, may offer opportunities for progress in vibration control in the future.

OK SA, me need to go clubbing now ( 8 PM local here ) . Will continue again soon.

just a thought

now that we've decided to sell the frankengun idea to the millitary, what about this

have a reasonably powered gun to shoot a new type of spear:
torpedo shaped gas cylinder. compressed air whistleing out its rear ensures good range without having to break the sound barrier when you shoot it. in the front of the torpedo is the warhead. a spring loaded double flopper slip-tip

the identity of the x-gun is revealed. its called the u-gun rofl

maybe we could incorpoarate one of those lazer guidance sysytems that gave us all the fantastic footage of iraq.
Mmmmm ....

El Grifferoonie, me matey, methinks you might just have given the 'spin doctor' a new idea ....


The spin would be created by the wings on the back of the shaft (alierons if you will - I don't think it's the correct term for aquatic applications) being moulded to form a 'spiral' ... this would make the shaft spin once it is lanched. I don't think having a barrel with grooves is going to do much good under water - I'm speaking of an enclosed track of course.

Still no comments on why you think Frankengun should be built?