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All About Guns What's your weapon of choice, and why? Discuss the beloved speargun here! |
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06-07-2017, 01:11 AM | #31 |
Shooter & Shooter
Join Date: Nov 2014
Posts: 955
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Re: Has anyone worked on developing speargun sights?
I made some for my airguns, though can't find all my build pics right now:
My build-log with a lot more pics is over on deeperblue: https://forums.deeperblue.com/thread...eargun.106583/ Last edited by Diving Gecko; 06-07-2017 at 01:21 AM. |
06-07-2017, 08:00 AM | #32 |
Big Time Bug Hunter
Join Date: Apr 2003
Location: Orlando
Posts: 3,097
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Re: Has anyone worked on developing speargun sights?
That is very unique and cool !!
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06-07-2017, 10:19 AM | #33 |
Joe
Join Date: Apr 2017
Location: Little Rock, AR
Posts: 64
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Re: Has anyone worked on developing speargun sights?
Regarding laser visibility under water: The dot is visible on the fish but not through the water itself unless there are particulates in the water. This applies to red and green laser beams since wavelength attenuation is minimal over 8m. The beam itself can be viewed more clearly if your eyes are in line with the beam when looking down the gun or over the top of the spear. But this is not how a laser sight is normally used or viewed. Normally the speargun is pointed at the head of the fish to be taken, the laser beam is turned on, the dot is placed 1" above the gill following the fish's movement and the trigger is pulled. In other words, deflection shots, two handed shots, oblique angle shots, shots from the hip and tracking shots are all valid methods to shoot fish using a speargun laser sight. Gun recoil has to be considered when going James Bond underwater but it still puts the shaft on target.
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06-07-2017, 10:34 AM | #34 |
Joe
Join Date: Apr 2017
Location: Little Rock, AR
Posts: 64
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Re: Has anyone worked on developing speargun sights?
Laser calibration on a speargun depends on the gun design and laser module placement. The preferred placement is behind and directly in line with the shaft on a band gun. If there is a flat, silicone the laser to the flat and adjust the laser so that the beam is parallel to the shaft. If the shaft has a flopper at 12:00, pull it up and center the beam on the flopper. Kona and Daryl Wong guns all have this feature. Pneumatic guns have a nice radius on top so the laser can be attached using the groove down the length of the laser's case as an alignment feature. Remember the beam is adjusted concentric to the laser's case using internal wedge prisms so it never needs to be calibrated itself.
If this approach isn't satisfactory, then there are beam steering optics that can be added. |
06-07-2017, 12:04 PM | #35 |
Registered User
Join Date: Apr 2014
Posts: 610
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Re: Has anyone worked on developing speargun sights?
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06-07-2017, 04:16 PM | #36 |
Joe
Join Date: Apr 2017
Location: Little Rock, AR
Posts: 64
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Re: Has anyone worked on developing speargun sights?
You have to look down the gun at the acrylic sights to make them work. Good idea though.
A laser can be added to the handle of a sling but the cost really goes up. But it works nicely. |
06-07-2017, 05:48 PM | #37 |
Registered User
Join Date: Apr 2010
Posts: 15
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Re: Has anyone worked on developing speargun sights?
Well, I actually experimented with laser sights (green, 30 mW, which is alot of power) about 6 year ago. As it was pointed out beam is not visible in the clear water during day hunt. Also it made gun sink and I was to lazy to add foam. Based on the experience - I can shoot hip-style much faster and accurate enough. Can be useful in target shooting in the pool especially if not under direct sun and it was working beautifully during my evening test sessions way back when I was working on the design. In the sea beam on the target was very visible 30+ feet but problem was to keep it on target, once it slips from the fish it was pain to get it back. Also 30 mW means that you can take someone eye in a split second so not recommended if you not diving with your mother in law. . But plastic high viz sight seems to be a brilliant idea. I'm thinking for rubber guns we need to reverse normal rifle sight design - two strips of high viz plastic in front (unless enclosed muzzle is used) and one in the back..
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06-07-2017, 09:49 PM | #38 |
Registered User
Join Date: Mar 2006
Posts: 4,245
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Re: Has anyone worked on developing speargun sights?
Speaking of green laser sights you can see one here:
http://waterprooflaser.com/contents/...Gun_Sight.html with some more info here: http://divesales.com/contents/en-us/d42.html |
06-08-2017, 02:13 AM | #39 |
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Join Date: May 2009
Posts: 3,292
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Re: Has anyone worked on developing speargun sights?
If you plan to aim at a target ... then hold that aim and then fire ... I doubt you will get good accuracy. Accuracy comes from timing your trigger pull correctly as the gun is going over the target. A lot of people think in the pool there is no movement, but that is only true if you go deeper than 2 or 3 meters. In a shallow pool there is more movement than in a hunting situation in the sea. So even in the pool you need to time your trigger pull to get any decent accuracy.
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06-08-2017, 07:00 AM | #40 |
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Join Date: Aug 2008
Location: Big Island
Posts: 5,098
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Re: Has anyone worked on developing speargun sights?
"In a shallow pool there is more movement than a hunting situation in the Sea." Majd, you often crack me up.
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06-08-2017, 08:52 AM | #41 |
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Join Date: Aug 2010
Posts: 1,145
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Re: Has anyone worked on developing speargun sights?
[quote=Behslayer;2143131]"In a shallow pool there is more movement than a hunting situation in the Sea."
Although I have never even shot a gun in a pool, I guess that can be true-If you are testing guns at a weight watchers pool party and everyone is doing cannonballs. And Reactive shots are taken only when necessary, as I aim at everything I shoot at (the head, as I hate to ruin the filets), and rarely miss. I think the idea for sights is totally unpractical offshore, with game fish on the move, and where things happen fast. Keep is simple-point and shoot Just my opinion, and you know what they say about that! I do really appreciate all the testing and posting you have done over the years Madj, as it is evident you put a lot of time and effort into it, but you just cant compare the two. Shelve the sight idea and lets see this new slip tip you've been teasing us with! |
06-08-2017, 08:58 AM | #42 | |
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Join Date: Sep 2002
Location: Zephyrhills, Florida
Age: 74
Posts: 2,512
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Re: Has anyone worked on developing speargun sights?
Quote:
I like the idea of a laser sight on a gun for hole hunting when you are guessing you shot placement because you cannot see down the shaft.
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06-08-2017, 09:33 AM | #43 |
Joe
Join Date: Apr 2017
Location: Little Rock, AR
Posts: 64
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Re: Has anyone worked on developing speargun sights?
The premise of a laser sight in Blue Water isn't to use the laser as the sole aiming device but to refine the point of impact to the exact moment when the trigger is pulled. The tip of the spear, orientation of the gun, angle of the fish and diver, distance from the fish, lead on the fish and even fish identification all effect the successful kill ratio. A laser dot on the target itself rather than a superimposed aiming point provides more information in real time to the diver. The helps sway the equation in favor of a one shot kill. That's all.
Now about a 30mW laser: That device could be Class IIIb but even that's alright if the collimated beam diameter is large so that the beam power density is dispersed. But other features must be included such as a beam attenuator, time delay turn on, key turn on switch, battery power interlocks and correct warning logo in order to be legal. And all of this additional power won't help if the dot isn't on the fish. Class IIIa or less than 5mW is more commercially acceptable, less hazardous and easy to manufacture and use when trained in the art. A Class IIIa (IEC 3R), 5mW 515nm green laser dot is quite visible on a pelagic fish at 8m in blue water. So the trick is to use an acrylic sight to get to the head of the fish and a toggled switched laser to aim exactly 1" above the gill. Bingo! This means that you don't even turn on the laser until you're ready to shoot. |
06-08-2017, 08:40 PM | #44 |
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Join Date: Mar 2006
Posts: 4,245
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Re: Has anyone worked on developing speargun sights?
A speargun, unless it is short model, has a longer sighting radius than most firearms, hence you have better angular discrimination when aiming it directly at your target or using point and shoot when seeing the length of gun and spear projecting out in front of you. For that reason, and the relatively short shooting distances compared with firearms, most spearfishermen don't need sights on their guns as the structure of the gun provides that (sear box roof, muzzle hoop or speartip). Some early band guns had a ring sight above the position of the sear box, the idea was you superimposed the ring over your view of the speartip as you looked along the shaft, the sighting line and spear trajectory coinciding at around 10 to 12 feet. This was due to the shot being slightly parabolic on a gun shooting a 3/8" diameter shaft, but eventually the idea was discarded as it was not found to be of much benefit once you became familiar with how your gun shot. An old Spearfisherman Magnum is shown, the metal ring sight could be folded down when not required.
If you look at Jack Prodanovich's classic alloy handle spearguns then you can see where that ring sight used to be fitted, the sight was discontinued, but the creases for the mounting position still remained in the casting. |
06-09-2017, 01:38 AM | #45 | |
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Join Date: May 2009
Posts: 3,292
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Re: Has anyone worked on developing speargun sights?
[quote=malibujohn;2143136]
Quote:
As for the new slip tips ... good news and bad news. Good news is that the tips have been tested with the welded tubed shaft with over large 30 fish landed without a single loss. The new tips I saw were easily the most gorgeous slip tips I have ever seen. Bad news is that the person testing those shafts brought in a bunch of them to me to test in my home pool ... and they failed accuracy miserably. Still not sure why ... but I think it was because they decided to weld the threaded tip on and that might have warped the tip. I could visibly see that when the tip was on there was a slight bend. So now the plan is to get some new tools that can guarantee absolute straightness to get the same accuracy and penetration results I got with my initial DIY shaft. On that test I had equal or better accuracy and better penetration than the best floppered shaft. I think that there is no reason to weld the tip on and it can be just epoxied on. Leaving a threaded tip also allows you to use existing slip tips that you already have (maybe that can be bad if you want to sell your own tip). There is also a possibility that the faceted tip is not a good idea and it might be vectoring the shaft off line ... maybe a pencil tip is a better idea. I know that sharp facets cut meat and bone better ... but if the shaft is veering off you lose accuracy and you shed a lot of power ... so all this needs to be tested and the plan is to put a faceted tip and a pencil tip and test them side by side for accuracy and penetration. A little more adjustments and I think it will be gold. Here is a picture of the beautiful new faceted tip ... I need to make sure that those will shoot as accurate as a pencil tip. |
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