Posts by popgun pete

    Just reviewing the Omer detachable handle guns as I now own all three versions picked up brand new for bargain basement, no name band gun money. The design was rather ambitious as they relied on using nothing but the inner barrel tubing from existing pneumatic speargun production. Most brand name spearguns are made by subcontractors, they are not in-house products, although the design parameters are no doubt drawn up by the company if they want something different.

    My guess is Omer sketched out the guns, the Airbalete comes first, and having done their sums figured they would not be making enough money if they made them in Italy. They could either abandon the project or find a cheaper alternative. Given the long delay between when the Airbalete was announced and actually ready for sale I suspect this was because they handballed the job to Taiwan and possibly asked them to make the guns as cheap as possible, but without going overboard. Given a free hand the Taiwanese factory began to look at cutting corners and that is how the guns turned out.

    I expect that the Airbalete production line was troubled by the need for a unique tank for each gun size as it is not like you can slice a length of tubing to the correct length as hydroformed barrels are made to size. No doubt looking for a way around this the Sporasub One Air evolution meant they could sell the same gun and just chop the triple hollow tube extrusion off to the required length. Another cost saving was these tanks are painted, probably powder coated,
    they ain't anodized and they have a rough texture as they are not entirely smooth. To provide a point of difference they also used a vacuum barrel muzzle using the STC system, that was a mistake as these use front tied spears, you can go back over half a century when those were used before.

    The last and best gun of the set is the Omer Air XII, it has a tubular tank of greater diameter and has dispensed with pretending to be a band gun based on the Omer Cayman handle design.

    Another fundamental flaw is the spiky bumps on the piston nose, they allow a gap to be seen through the relief valve ports. If you want to smash up plastic shock absorber anvils then you need a meat tenderiser mallet, Omer put it on the nose off the plastic piston! An admission of "we done wrong" is the spare shock absorber anvil supplied with the guns in later years. What to do about it is take the piston out and flatten it off ensuring that at rest the piston seals don't poke out the front of the end of the inner barrel tube. This last boo boo is handy for letting formerly trapped water out of the space in front of the piston with the gun discharged, but not at the expense of smashing shock absorbers and possibly the piston itself.

    While drilling these holes it is best to use a small drill, I used a 3/32" diameter drill bit. Basically you drill one at the bottom and two either side just above the alignment of the fat diameter grip attachment pin, all holes lying on the annular well in the back of the gun. The spigot in the centre of the well is essentially the inlet valve cap, so don't scratch it. The three new holes may come out in not exact alignment due to the angle you hold your power drill on, but don't worry about that as it fingerprints your gun as no two guns will be exactly the same. Originally I only planned to do two holes, but there is enough meat in the bottom of the handle connection so that it will easily take three. Omer should have done this themselves, but then they probably never thought about it.

    The Omer Airbalete/One Air/XII removable grip handle drain fix. Use a small drill and follow the outer edge of the well in the back of the handle. With three extra holes you then have four drains as at the top the trigger push pin already has its own hole. Now at any angle water will drain out with the butt down and you definitely need to get rid of any saltwater trapped in there. Quick to do, it has taken longer to type this up.



    Responding here, even though water under the bridge now, those involuntary discharges were due to the dipping sear tooth designs not always pushing the sear tooth right up into the shaft tail notch. The trigger and sear lever were latched, their release is momentary during the shot and then they re-latch via the biasing springs pushing everything back into position. But it can be a false signal as with the tooth not fully into the spear tail notch any extra band load and the shaft can escape the gun without you pulling the trigger. The dipping sear tooth idea was pioneered by Sporasub many years ago, but copyists made changes to circumvent their patent and those clone guns could often fail. One new company made a Rob Allen clone in Australia as they were unable to source Rob Allen guns, from memory it was Aquastralis, and that gun was a dud due to trigger problems involving misfires. They eventually found a fix as the tolerances were affected by the plastic trigger parts swelling with water immersion, but their reputation was by then ruined and the company turned turtle. Their gun prices tanked in the marketplace. Strangely their different handle design won an Australian Design Award based on external appearances, but it was lacking in the innards department which is what really counts. No one was accidently shot during this debacle, which was very fortunate.


    Here are the Sporasub patent drawings, Hugh Dessault was the inventor according to the patent. One source of problems was some changed the spring orientations in the trigger mechanism in order to be different, that made the mechanism somewhat marginal in functioning properly and then misfiring and jamming complaints flooded the forums as a consequence. The dipping sear tooth guns got a bad rep after that. The sign of a dipping sear tooth gun is no backing projection behind the sear tooth, the former is what causes the sear lever to roll up or down in the sear box when the spear tail hits it during spear insertion into the gun.

    Below is a standard trigger mechanism showing the sear tooth and the backing projection on the sear lever. More examples are shown in the parts photos.

    Master speargun builder John Warren who specialised in using the Prodanovich high capacity handle for shooting game fish has kindly provided the text for his web page on Paul Horolan which is no longer up, being part of the former Rocknfish website.


    Hawaiian Speargun - Paul Horolan

    All photographs provided by David Preston, Oahu, Hawaii.

    David Preston from Oahu, Hawaii recently brought a very interesting speargun to our attention. This specimen appears to be hand built from oak wood and preserved with many layers of varnish. It has a rifle like 'stock' behind the hand grip. The grip is in an elevated position assuring accurate trajectory of the arrow when fired. Streamlined appearance is joined with several traditional Pacific island speargun details. This is a very attractive and functional gun. It's origin was mysterious, but with some research and collaboration from world-wide spearfishing experts, the origin of this interesting piece seems to have been established.


    The gunbody is 54" in length and 1" in width. The handle has additional koa wood laminated onto it. There is a rubber pad on the gun butt. The spearshaft is 1/4" in thickness and appears to be made from carbon steel (probably heat-treated spring steel obtained from a 'Hinge Gun'. The overall length of the spearshaft is 56 1/8 ". Over all length is 64 1/8". This information has been provided by David Preston.


    This nicely crafted piece of functional equipment was a mystery, until Ron Mullins contacted his friend John Iwaniec on Oahu, Hawaii. We were fortunate because John was definitely the right guy . A year ago, John had been introduced to a 75 year old man named Paul Horolan who has been making these spearguns in a town near Pearl Harbor. One of John's close friends owned one of these guns himself. He recognized a similarity between the spearguns John had made and the ones which were originally made by Paul Horolan. The introduction between the gentlemen speargun builders was destined because they both had converged upon a successful ergonomic design - the rifle stock attached to a rear-handled wooden gun. On another page, you will see the similarity between the speargun made by Paul Horolan and the speargun made by John Iwaniec.


    Details of Paul Horalan's Hawaiian speargun

    The Paul Horolan speargun uses a mix of design elements which have been seen from the Pacific Islands to Japan. Note the trigger is a bent piece of stainless steel rod which forms a round hook. This hook protrudes through the flattened, spring steel spearshaft. The trigger is spring loaded with a stretched length of natural latex rubber tubing, secured with a knot below the trigger guard. This pre-tension assures the trigger will be in place when the spearshaft is introduced below the copper shaft keeper. Two bands are hooked to the single 'tab' brazed upon the spearshaft in front of the shaft keeper. When the diver pulls the trigger the stainless rod is pulled down from the hole in the shaft and it can fly free to it's target.


    The bands are attached to this gun in a manner which more closely resembles the small Japanese rollerguns we have seen. Strong D-rings hold the bands. There is a continuous stainless steel strap which secures the D-rings to the front of the gun without weakening the wood with a large hole. Note the ligature on both of the bands. The two bands are made from a single length of black speargun rubber.


    Spearshaft details of the Paul Horolan Hawaiian speargun

    This spearshaft appears to be spring steel, much like which is used in the 'Hinge Guns' commonly used around the shallow reefs of Hawaii. The spearshaft is 1/4" in diameter, relatively thin in comparison to most of today's guns. No doubt the arrow really was quick. Double wings helped secure the impaled fish. A stainless steel slide ring was used to retrieve the shaft. heavy monofilament line was used to secure the fish.


    We are grateful for all the quality photographs that David Preston of Oahu, Hawaii has provided us with. The excellent quality of these images allows us all a visual window by which we can discover work by one of the old master speargun builders from Hawaii, Paul Horolan.

    A Google search on Paul Horolan turned up nothing, so I decided to check for an obituary in Hawaii and this came up. There were a few results for a “Paul Horolan”, but I think that this is the most likely one. I have not retrieved the entry yet, so for now this will have to do.


    More images of Paul Horolan’s earlier gun judging by its use of copper elements for spear and trigger mechanism. It is interesting to note the Japanese pre-war rollerguns similarly used brass parts, another copper based alloy. The advantage is these parts don’t grow with rusting as steel does, but are much softer, hence are limited for use as spears against tougher prey.



    Reverse tooth and pin restrained guns were a valid solution for many early guns, in fact another one is the Australian made "Mare Dama" which was a cast alloy frame speargun. However any similarity ends there. Mel Brown who manages the AUF Spearfishing Museum supplied the images of this strangely futuristic looking gun, however that would only be if you knew zero about spearfishing, but like everything back then it was a product of its time.



    I had come across Paul Horolan some years ago when investigating the progression of underwater weapons from the earliest days. Many divers made their own weapons as production spearguns were either unavailable in their locality or would not be suitable for what they had in mind. With the right skill set and imagination they often created their guns from first principles. One of these talented individuals appears to be Paul Horolan. My fellow investigators John Warren and Ron Mullins pooled our info and checked out the most promising weapons with a unique aspect to them, being senior divers we had seen a lot in our time in the sport.


    The first Horolan speargun we saw was this one, here is John’s presentation of it.


    We can see that this gun has a pin that the trigger pulls down to fire the spear rather than a sear tooth rolling out of a spear tail notch. This system does not require a sear box roof as the shaft is basically hanging on a hook and pulling the trigger the spear tail is essentially wiped off the hook as the pin descends. This is very similar to the reverse tooth guns as shown in the trigger mechanism rules diagram.


    With a bit of image manipulation we can put the spear in the Horolan gun. It is notable that the sear box mouth is raised above the gun top deck and that the spear rides above it. This is reminiscent of the Sampson gun where to defeat spear initial column bending deflection under band load acceleration which could then bounce off the barrel tube creating subsequent inaccuracy a large gap was used between the spear and barrel. The Sampson gun also used a 3/8" diameter shaft just to make sure a large hit could be delivered with shaft momentum at the target, something the Horolan gun does not need, using a far slimmer and faster spear at medium range targets, the gun already reaching part way to the fish.



    The Horolan guns use a single-piece trigger with a long trigger arm that provides more space for multiple fingers on the trigger. The metal shroud muzzle is a form of hoop muzzle to allow a tabbed shaft through and the rubber band strands are anchored in hinged metal links.





    A passive metal spring line clip controls the shooting line, you can see it on the LHS of the upper grip.

    The large variety of speargun designs in earlier times reflected the environment that they were used in and the species of fish sought. An example of this are spearguns used in tropical waters where the fish the locals are interested in are not necessarily big ones and they cannot easily be cornered in reef structure thus requiring a straight shot to bag them. Keeping the energy expended vs energy acquired in foodstuff consumption means few shots as possible are required. As aiming not to miss requires a long barrel and spear the guns need to be slim profile to have wand waving ability with small course corrections usually required as the oblivious but perpetually nervous prey charge course in their own hunt for sustenance.


    In Hawaii Paul Horolan crafted his own unique timber guns to meet these requirements, their most notable feature being a combined timber grip and butt stock that worked as a rear paddle to brace against with the inner forearm. Thus the long gun can be shifted with one hand for minor aiming adjustments. These great looking guns have all their parts crafted by Paul. Because of the large buoyancy incorporating a large weight of stainless parts is largely offset by all that lumber. When making my own timber guns it seemed appropriate to also use a wooden butt stock to offset the all metal mechanism weight, but I never attempted such glorious timber work as we see here. All metal mortice trigger mechanisms were common in timber guns.


    were common in timber guns.

    Resetting the releasing valve for the next shot you push the rear butt forwards against its internal biasing coil spring. You cannot screw the rear butt right off as it travels between set limits. Dismantling the gun you can, but that involves undoing a few more parts. Although I have never done it some indicating marks could be added on the control knob surface to provide a set of different power positions which you could then in a sense dial up, say one or two alternatives as more than that and you will just confuse yourself.

    A schematic showing how the power regulator works by closing the gap for the releasing valve to fly backwards into when firing at reduced power. The throttling effect of the reduced valve opening is used to slow the gas flow which limits the pressure build up rate in the inner barrel. Unlike the bulkhead partitioning system the Alpha C1 gun uses all the stored air from muzzle loading for the shot. Diagrams show guns shooting, top one maximum power, lower one reduced power.