Travel tube gun idea for split spears

[popgun pete]

Originally Posted by popgun pete

[quotentend makimjg=Alec;2191909]I’m sure you’ll sell thousands of these tubes

I don't intend making any guns like this, the idea is simply up for discussion, plus I already have two travel guns and have not bent the spears yet, but then I don't use them very often. JBL made a two-piece spear as well as the one supplied with their “Travel Magnum”, it had a short tail of 316 stainless steel at 3/8” diameter and the front section was spring stainless steel at 5/16” diameter. Not sold as a travel gun spear, it still showed that a two-piece spear is a workable proposition and the step in diameter made for a line slide stop.[/quote]

Here is a photo of those two shafts, the Travel Magnum shaft is about a 50:50 split, the supposed Adapta-shaft is just the 3/8 inch diameter tail. I obtained the latter in a job lot of shafts, shafts being akin to ammo, they get used up. I generally used a full length shaft with the Travel Magnum, leaving some spears with my interstate dive buddy for the annual harvest.

[spearq8]

A friend of mine is really into making powerful double roller guns using the travel system. He uses a 9mm shaft that is cut in the middle with threads. I personally can't imagine ever using something like that ... but he has sent me videos where he is landing some good fish with it. It seemed to retain reasonable accuracy as some of his shots were from long range. Maybe there is not so much tension in the center of the shaft so things are not so bad as it seems. I could also see that using it with a slip tip in open water could be workable. In the end this is a solution where you only go for when you have no other options. If your choice is between no speargun or a travel speargun ... then it makes sense.

[popgun pete]

Well one of the longest running take down spearguns, the JBL Travel Magnum, was supplied with a breakaway tip for that very reason. However as the old Voit and later JBL spearguns were saddled with a rather ordinary trigger mechanism, which has been thoroughly analyzed elsewhere, those guns dropped in popularity. The last lot of Travel Magnums had blue anodized barrels, in fact just searching there are still a few around for sale.

I also vaguely recall a Lightning version with a smaller barrel tube using the Explorer barrel. The Explorer handle was identical to the Magnum handle but lacked the knuckle guard on the grip and had a smaller boss to take the smaller 1 inch diameter tube, the Magnum guns all using 1.25 inch diameter tubes. I doubt these Lightning guns were floaters after the shot as the Travel Magnum floats, but only just with butt down and the muzzle barely poking out of the surface. I know because I use one. You need a good grip on the Travel Magnum as being careless its butt can knock your teeth out with three bands powering the shaft as the gun is too light to fire a 3/8" shaft. In the old days the Magnum guns could cope with such shafts as the gun were full of water, sealed barrels came later. A double handed overlap grip and you have no problems.

What people are now looking for is a eurogun, as they have become all the rage, that is a Travel Eurogun. However euroguns use slim spears and they don't lend themselves to splitting unless the overlap is relatively long where the shafts join and that is why few such guns are offered. Once they show shaft busting problems word of mouth travels fast and the product is killed off.

Actually this gun below is the Lightning smaller barrel model which I doubt was a floater after the shot, if that grip handle is still cast alloy.

[popgun pete]

Well surprise, surprise, JBL do offer a Travel gun, here it is.
https://jblspearguns.com/products/re...pr_seq=uniform
Never thought to look before this!

[popgun pete]

An advert for the Lightning Travel Magnum had the following specs sheet, but the barrel diameter is wrong and seems to be that for the full size silver barrel gun. Just measured an old cast alloy Explorer handle and the front boss is 0.90 inch diameter compared with the Voit-Swimaster-JBL Magnum handle front boss which is 1.16 inch diameter. The rear boss for the cocking stock tube is exactly the same as the front boss on both handles. With barrel tube wall thickness added that works out at 1 inch diameter for the Explorer and Lightning and 1.25 inch diameter for the Magnum guns. The slimmer barrel guns are intended to improve the wand waving capability of the gun, but I don't wave my guns around underwater, I swim them around.

Found another blue set, but these are the full size barrels. The author of the article showing these images said that it was a Travel Magnum Combo set, but looking closely there is no join in the long gun's barrel, so maybe these are just two JBL guns and not a travel set.

[popgun pete]

And now for something different, a twin tube barrel carbon fiber cable rollergun with a rear mounted band battery.

Note first image below is another version. The last image is one that has been hacked about by me to gain a view from what had been separate images to gain an overview, but the resultant image is somewhat crudely stitched together.

[popgun pete]

Note the above gun is a single draw rollergun, the slack band length on a standard gun is sent back on the gun to sit behind and alongside the handgrip. For the gun to work it uses a long cable wishbone to draw the bands pulling from the top deck. The advantage of a reversed gun is the muzzle can be made small, this being a cable rollergun. Everything depends on the cable running without losses through the rollers, the only energy loss being that to spin up the rollers. You need to be sure your hand does not get into the bands at the back end of the gun. That is why the Arrow Gun has shields. The original gun is a sort of crossbow using bands, the bow being a metal frame supporting rollers and it has a cocking system with part of the gun body pivoting. We don't need those parts in a speargun.

[popgun pete]

Here is another travel gun from New Zealand, never seen one before, but their advert spells out what it is pretty clearly.

[popgun pete]

It seems Alemanni has taken a different approach to his latest travel gun spear. Instead of making two parts combine into one fixed shaft he is using a taper at the spear join not unlike a breakaway head. There are lashing hooks on either side of the joint where a short piece of line straps them together. The idea is the Morse taper connection will part under the pulling load of a fish with the fish now connected by the front of the shaft closely followed by the rear shaft which your shooting line is connected to. The fish cannot bend the shaft because it only exerts twisting force on the front half shaft, the rest is trailing behind. If the central tie fails then the fish swims off with the front section of shaft and you get to keep the rear half shaft. For general gun handling the taper will keep the shaft halves together and will not fall apart due to gravity alone.

https://youtu.be/p7cY3qIIWrs

[popgun pete]

Although the details are not entirely clear I think the spear connection looks like this. The principle being used is that you only need the shaft in one piece for reloading the gun and swimming around with it, especially if you point the gun downwards you don't want the shaft falling apart which would be highly inconvenient. So the taper jams the shaft just enough to support its weight. Once the shaft hits the target you only need its parts to stay connected, they don't need to be one long piece. The other requirement is when you miss, it is possible with the gun set to a number of wraps, usually two, the spear will hit the stops and pop apart, but I guess you can live with that, On dry land the taper can be set a little tighter by bouncing the shaft tail on the ground letting its weight do the setting, but you're unlikely to be able to do that in the water.

[popgun pete]

An analog of this is the pneumatic speargun piston. These have been made of plastic since the seventies and the tapered bore in the piston nose jams the spear tail so that the spear does not fall out of the cocked to shoot gun. In most modern guns the taper is on the spear tail, not the piston nose bore and as that hole wears the spear tail gradually goes deeper into the piston. In the metal piston days I had a spear tail wear so much that eventually it would not stay in the piston, but this is pretty rare as spears would be usually lost or bent before that happened. This was one of the older shafts made of much better stuff than what followed later and dated from the days when engineers decided the specs and not the company bean counters.

[popgun pete]

After winging its way here over the wine dark sea here is the first photo of the JBL Reaper Travel Gun. A bit bigger-boned than I expected and I am just glad it got here so soon. Shipping box was very strong with big flat staples that I prised out very carefully, if you ever get snagged on one of these you don't do it twice.

[popgun pete]

The spear is an integral tipped shaft of 8 mm diameter and has a mono loop through the extreme spear tail, which is not my favourite rig. There are no stop lugs on the wishbone notched shaft. The rear end sinks when tossed in the tub, the front end floats and has fat, rather long bands. The carry bag is the same one used for the Magnum, right down to the strap placements. Overall the gun looks pretty good, a bit on the small side and I could see a triple break-down version with an extra intermediate barrel tube. A longer spear to match of course. The guide track is built into the barrel tube extrusion, at the ends where it is blended over there is no anodizing, so the parts were cut off later.

[popgun pete]

There is 5 meters of black mono between the end crimps on the 100 cm Reaper, the gun itself from butt to tip is about 1.30 meters with the exposed metal barrel tube just on 100 cm. So counting the length running along the spear that is two wraps which is really all you need. I haven't installed the rear loading butt which is rather short, so didn't include that in the overall length measurement.

The trigger mechanism is a cam lock as it dry fires, thus pull the trigger and the spear moves forwards a tiny amount. The dipping sear tooth mechs like the Sporasub's and early Rob Allen's the action of release is momentary so they don't dry fire, hence no way to check the action on terra firma unless you have someone pull on the shaft as you pull the trigger.

Photos of the latest Rob Allen mech shown below, the JBL will be near identical, especially as the line release finger is now also metal on the JBL. The disposition of the springs may be different in the JBL, but to check will need to knock pins out.