Japanese Rollerguns owned by Don Paul, his photos

The curiosity about Japanese rollerguns arose when John Warren wrote up a dissertation on an example which had been presented to Jack Prodanovich. People often sent underwater weapons to Prodanovich for him to examine and perhaps pass judgement on them given his experience and powers of observation and insights. Prodanovich and his colleague Wally Potts took spearfishing from the realms of weak peashooters to the big game league.

The rollergun he was given is a refined piece of woodwork and made with an eye to quality and must be a very early example. Here we can take a look at it with the forensic photos provided by John Warren.


Above Jack Prodanovich holds the diminutive Japanese rollergun made in Osaka, Japan.



Here we can see that the brass rollers have a concave surface that allows the flat bands to auto track on the rollers, whereas in later guns they are flat surface drums with a small flange on either side in order to simplify the construction.

Here we can see the neat brass casting work on the rollergun’s sliding carriage. The porpoise back hydrodynamic shapes seen on the “King” gun’s sliding carriage are at this stage in the far future.

Part of the assembly of this rollergun is done with brass nails or tacks, there are not the brass screws that are seen on later examples. The anodised nameplate bears only Japanese characters.


Note the flat brass fender straps that extend forwards to the ends of the roller axle, these are to keep the shooting line from being gobbled up by the roller band drive system during the shot. This feature also tells us that the gun carried line wraps strung rearwards of the roller axle. Next to find was the line wrap rear hook.

And this appears to be it, the lateral prong is on the end of a swinging link, behind it is the brass rod link that pulls the trigger with a rubber band acting as a biasing spring. There are no metal coil springs in any of these rollerguns.

Now the question was did this little gun have enough power reserve to throw some energy away by using a passive line hook that would bend with each loop release or did it work in some other fashion, especially as it was on the end of a link arm that could swing. Plus where was the safety on this gun to prevent jerking as the bands were dropped in on the sliding carriage hooks and firing the gun prematurely? It then occurred to us that this swing arm did two jobs, one was the safety as it engaged the trigger pull rod brass loop to lock the trigger from moving and when swung to the opposite side it was a swinging line release lever. By swinging to the side as the shooting line pulled with the shot it would then deliver the line wraps their freedom as they passed beyond the flat rubber band drive system. If so, then WOW!

This ingenious concept has never been tested, but it was drawn up on the generic diagram for this gun type shown here. Red rubber flag is the frictional detent for when the line wrap function is being used, the rubber tag passing through a brass loop which with not much effort it is pulled out off as the gun shoots and the shooting line begins to haul as the spear heads towards its target.

Red swing arm hooking the trigger link running forwards to its biasing rubber band is the safety function, green it is the swinging line release rear hook. Front line wrap hook is the forward brass ring under the muzzle which is also the shooting line anchor. Shooting line wraps are shown in blue.

A now discontinued web page from speargun builder and renowned Rocknfish sculptor John Warren.


Ron Mullins has a very extensive collection of vintage spearfishing equipment. Among these antiques is a very high quality example of an Asian rollergun. Another example can be seen in Jack Prodanovich's personal collection. These small production spearguns used flat rubber bands which were probably hooked to the sides of the shaft carrier with brass rings. The example that Ron has still retains the rings, although they are temporarily fixed to the end of the spearshaft. It is also important to view the red plastic carrier stops on the carrier guide rods. These stops absorb the energy of the carrier, as it still is powered when the shaft is released. This gun (large size) used two flat bands as is indicated by the double rings on the side of the gunbody.

Note that this advanced version of the Asian rollergun has an exquisite small line reel that is stored in a cut out compartment in the bottom of the gun body. The small brass reel has knurled side plates which undoubtedly assisted in line repacking and drag during deployment. In the photo below, you can see the double rings which held the flat bands. The line deployment is uncertain. We do not think it was hung from the hooks on the shaft carrier mechanism.

This small rollergun is the large size. It has a red color english language nameplate. Some components around the trigger are missing. The ring on a rod protruding in front of the trigger may be part of the line release or safety mechanism.


A close up of the red colored name plate reveals the words, "U.W. Spear Gun, TAIRYO, Large Size, Pat. No. 408908, Made in Japan. This nameplate most likely indicates a post WWII manufacture date.

Since the above page was written we now know the flopped down brass rod link on the trigger is to its biasing spring rubber band which anchors on the brass ring directly in front of it. Possibly this gun shot directly off its reel, but that adds drag to the shot, so not very likely. With parts missing it is difficult to draw definite conclusions on this one. However over the years these guns have been coming out of the woodwork to use a phrase, but still no feedback from Japan.

Another Japanese hand crafted speargun that is a descendant of a raft gun is the Hiroshima gun. This speargun was being offered about 20 years ago by some old time craftsmen who no doubt have passed on by now, their business disappearing from the web. I remember they offered a Hiroshima gun with all its accessories for about a thousand bucks, and that was way out of my league back then. Of course now I regret not buying one as you got a forged spear and a precision crafted weapon.



I only mention this gun here because of the expert craftsmanship as exemplified by Jack Prodanovich's early Tairyo rollergun. These guns are deceptively hard to make and getting everything to run true, they are not churned out by sweat shop labour. Simple in appearance, but demanding of every precision. The Hiroshima gun has a horizontally spilt front timber stock that the spear is driven down by multiple band pairs holding on to the winged shaft tail running down side slots, but these slots open all the way through to the split muzzle. This type of gun in Japan is known as a sword gun due to the likeness of the gun body being the sheath for a Katana, the samurai’s sword. Check out the wing tailed shaft and the bifurcated blade speartip.

In addition to the Nakaoka HB2 diving speargun shown above the company also made a HB5 version seen below. The raft gun version had an extended rear stock like a pole and the trigger was pulled using a cord running down the pole so that the gun could be fired from the surface while angling the pole using an underwater look box to line up the fish. Decoy fish were also placed in the water to lure in the more timid specimens.

Almost makes me want to pull on my Kongo of Koga ninja outfit, run out into the streets shouting banzai and jumping backwards up into trees while hurling shuriken in all directions. Older divers will understand the reference.

Whist, whist, whist, whist ….. klong, klong klong, klong. Four "star knife” hits, usually into a tree!

P.S. Found this letter on the Nakaoka gun.

While we are discussing Japanese spearguns there was a Japanese English language web-site for "Nakaoka" spearfishing equipment which was viewable on-line a few years back. The "Nakaoka HB2 model" speargun was made from teak and had a rear wooden pistol grip handle configuration. Most unique feature was the thick timber barrel which was split horizontally running from the trigger mechanism right through to the muzzle. That produced a thin deep slotted groove on either side of the gun barrel at about the mid-line of the stock. These long side grooves were necessary because the spear shaft ran in a totally enclosed track located out of sight between the upper and lower halves of the rectangular cross section stock! The spear tail was fitted with a horizontal plate with short rearward curved fins, like the fletch of an arrow, whose tips projected out of the narrow grooves on either side of the gun and served as shaft tabs. The slim, round section rubber drive bands were terminated by flat metal (think of a paper clip shape) loops that hooked onto these projecting fins. The rubber band strands were trussed together in pairs to form a separate rubber loop for each metal loop end, there being two rubber loops used on either side of the gun to hitch onto the projecting metal fin tips. So the grand total of rubber band strands was eight, with them being formed into four looped pairs tied together with cord at either end. One end was tied to the metal strap muzzle frame, basically an anchor point, and the other end was tied to the flat metal loop. The split muzzle thus had two band loops tied to a metal frame on the top half of the timber barrel and two band loops tied to a separate metal frame on the bottom half of the timber barrel, with one loop on either side of the gun and thus essentially being tied to the four front end corners of the bifurcated timber stock. This strange band anchoring arrangement allowed the fletched shaft tail to clear the barrel without fouling on the band anchor positions at the muzzle and when tensioned up the combined action of all of the rubber bands held the two halves of the split barrel together because the top loops on either side pulled down on the muzzle and the bottom loops on either side pulled up on the muzzle. The stored shooting line ran along the flat top deck of the gun through some metal rings before being deployed. The spear tip was a double long tine fork oriented vertically so that when sighting along the barrel you could see the upper tine projecting up into your sight line. This was necessary because the spear was buried inside the timber stock, being somewhat like a pneumatic gun in terms of aiming the gun. An optional five tine tip was available in the HB5 model, this model actually being referred to on the web-site as a "diving gun". Basically the HB2 and HB5 were the same gun.

Another version of the "Nakaoka" gun was built into a long pole and a pull cord operated the trigger mechanism in a remote fashion so that the user remained high and dry while standing on a raft and holding the rear end of the pole. Part of the raft fishing kit included underwater look boxes and submersible fish decoys (something along the lines of rubber ducks for duck shooting) which were designed to lure their unsuspecting fishy comrades to an untimely end.

This style of speargun was referred to as a traditional "Hiroshima gun" that had been manufactured by Nakaoka for 40 years (from memory this was back in 2003), but the web-site looks to have since vanished from sight. Price of the spearguns was around US $700, bearing in mind that every part was expertly crafted using traditional Japanese metal and woodworking methods. I had some saved images of the gun, but have yet to find them. I am sure Don saw these guns at about the same time, a guy in Japan had indicated their existence and provided the URL in an e-mail.

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It is possible that the Nakaoka gun is also a conceptual rejig of the French side-slotted barrel gun where the winged sliding pusher is now transferred to the spear tail and the barrel tube slots are replicated by the horizontally split timber stock, the Nakaoka gun certainly fires in the same fashion. Making that spear and its delta form tail is no mean feat as it has to be completely flat to ride along the timber running slots without carving them away with successive shots.

Another sword gun is this much more modern version, but it too buries the shaft inside the timber stock, the ultimate closed track gun as in how closed can you get!

One might ask the reason for the sword gun and the answer must be for someone to score on nearly every shot. The long reach of the gun in extending most the way to the target, the minimisation of angular aiming errors on such a long barrel and the fish being relatively small it should then be in the bag. Almost a controlled captive spear jabber, those gun types are also found in Japan where the spear never completely leaves the gun. Just how this one works is not immediately obvious and I have yet to completely work it out, unfortunately the guy who built it does not show us the spear tail. It may well be that a sword gun is not a totally enclosed track, but in fact a captive spear jabber. In that case the Hiroshima gun is not a sword gun as we know it has a shooting line strung on tip of the the barrel. Spear jabbers don’t use a shooting line as the spear is captive.

I have been advised by a colleague that there is a version of the Tairyo rollergun that bears a nameplate written in Chinese. Here it is.

The most recent nameplate that I have seen is this one.

I know nothing of Asian writing forms, but the running man symbol if I can call it that appears on both.

Tairyo new type.

Another Japanese rollergun has appeared on eBay, this one has the swinging arm safety also seen on Jack Prodanovich's specimen of the gun. This example is a longer version and appears to lack an anodized nameplate. The deflection straps or side struts that keep shooting line from tangling on the rollers are not present either which indicates they were either a later addition or are unnecessary if the shooting line is held by a passive clip under the front of the muzzle which is seen on the "King" model of the guns. Any shooting line wraps freed from a rear mounted line hook release arm have to clear the roller axle without snagging during the shot.

This is a Japanese rollergun owned by Ron Mullins who took the photos. It is basically the gun that the line drawing presented earlier was drawn up from and has some differences to the ones usually seen. The hooks that are on the brass carriage are now located on the sides of the timber barrel with the bands now fixed on the sliding carriage instead. Hence to cock this gun the bands are pulled back from below rather than on top of the gun. The sliding carriage is a flat top plate with a second plate riveted or soldered on beneath it which contains the pressed troughs that form the tunnels that the twin rails run through which makes this carriage much lighter than the cast brass version. It is also more flimsy. The most notable thing about this gun is that it still had its red rubber bands, although they have completely rotted. As usual its detachable spear tip is missing. Only one other like this has been found to my knowledge.


My guess is that despite the dynamic benefits of the sheet metal construction these simpler to manufacture guns didn't have the look of the cast metal versions. Given that people were buying what were hand made weapons for possibly significant amounts of money they preferred the more substantial looking guns and my view is that would be true today, only now as wall hangers.