New LG

[popgun pete]

This new "Black Head" muzzle and nose cone is what I had been expecting on the original LG-SUB gun as hydraulic lock makes it near impossible to push sealed sliders into the muzzle unless you simultaneously move the piston back a little or tip some water out first or the vacuum cuff has a one-way valve action to let water out, but not in. All the rubber conical nozzle seal guns have this valve feature, which is the system used by the majority of pneumovacuum guns. LG-SUB needed an underwater loading capability, especially on their longer guns and now they have it for all of them with the new longitudinally ported muzzle using a ring of forward facing outlet ports just rearward of the muzzle nose.

 

[popgun pete]

The new muzzle (testata) will be featured with other new LG-Sub product releases here:

European Dive Show Bologna
Location: Bologna - Italy
Date: March 1st to 3rd, 2019

The Italian Dive Show takes place every year in Bologna and is already in its 26th edition. This event primarily targets scuba diving, sport fishing and freediving fans. This show, less known to the international general public, is still one of the major European events. For this new edition, which will take place from March 1 to 3, 2019, the organizers expect around 250 exhibitors and 11,000 visitors.
https://scontent-syd2-1.xx.fbcdn.ne...=4c3518365287b8e6f0a3d061f9c01582&oe=5D242962

 

[popgun pete]

Also being announced at the show are these new integral tip spears with black plastic flow cones forwards of the flopper.

Personally I would like to see removable points with built in flow cones that screw on just forwards of the flopper for quick replacement when the shaft hits a rock after passing through a fish that is backed up and stays with cover.

Here is one from Pelengas, it looks like the extreme point itself is replaceable.

 

[Diving Gecko]

Yeah, the need to tip the gun out of the water before inserting the spear is kind of a deal breaker for me - and I didn't even know that the LG was like that until you posted that video. I hope many spearos wont mind, but if it was me, I might forget from time to time and that might lead to troubles down the line. Good to see they thought of a fix. I hope they wont price it to high as honestly, I feel a gun of that price should have had one from the very beginning.

 

[popgun pete]

Yeah, the need to tip the gun out of the water before inserting the spear is kind of a deal breaker for me - and I didn't even know that the LG was like that until you posted that video. I hope many spearos wont mind, but if it was me, I might forget from time to time and that might lead to troubles down the line. Good to see they thought of a fix. I hope they wont price it to high as honestly, I feel a gun of that price should have had one from the very beginning.

I don't know if there is a connection, but a month or so prior I had written to them about replacing the rear inlet valve cap, which was missing, and queried if the water had to be tipped out of the muzzle before reloading and speculated here on small bores running rearwards in behind the muzzle seal with a rubber annular ring valve to eliminate any hydraulic lock, a system we had been speaking about some years back when the "Tomba" was being developed. Here the small water escape bores would have to run rearwards rather than radially because the LG muzzle is very short. Now it appears that they have actually made it! However I don’t see the rubber ring valve in the new “black head”, but something must do that job to prevent water sucking in as the spear loads into the inner barrel.

Just checking back this is what I said to LG in mid-January (actually 9/01/2019).
I watched the video, the muzzle loading is as expected and very familiar to me. Did I notice the rifle was reversed to run out of water, to avoid hydraulic lock? For this rifle it is held above the surface. Otherwise the line slide cannot seal in the head, is that the situation?

 

[popgun pete]

Here is a video showing how the LG-Sub handles are milled out of Delrin. Much slower than injection molding, however changes can be made by altering the cutting program and sections can be thicker as there are no cooling time restrictions or mold filling considerations.

Now you can see why the guns are expensive!

 

[popgun pete]

Last year LG Sub created a new “Supreme” model which has a 14 mm diameter inner barrel. The advertising blurb at the time stated that this was a first for pneumatic guns, but those with long memories will remember the GSD guns that also used this size and of course the Alpha C1. The larger barrel allows the gun to use larger diameter spears and this table shows their current model line-up. The previous “Revolution” has a 12 mm inner barrel.

 

[popgun pete]

 

[popgun pete]

The only detail photo I have found is this one in the LG-Sub catalogue. You can see an X-ring sitting in the entrance of the alloy muzzle tube. The black plastic section carrying the short "light pipe" red sight rod and line wrap hooks is what LG-Sub call the ogive and is basically the nose cone. Because the tapered nose on the alloy tank forms part of what would be the nose cone on a cylindrical tank gun that means the front bulkhead is just that much smaller. Externally the alloy muzzle tube is a simple cylinder with two flats just behind the front screw thread so that the muzzle can be tightened up on the inner barrel tube. That front screw thread is what the plastic nose cap screws onto, this part being the "black head". This front cap has an entrance bore that is a close fit on the machined plastic line slides which are a form of Mamba sealed slider. When this front cap screws on it holds the X-ring in its seat in the front end of the alloy muzzle tube. There are 6 radial ports in the plastic nose cap that are at the back of the short troughs cut in the periphery of the cap which are to let water out when you push the slider in. It appears that the ring of 6 ports coincides with the front of the X-ring.

I have added some white lines to highlight where the tightening flat is on the alloy muzzle. When the front cap is screwed on it butts up against the front face of the ogive, which means the length of screw thread and the flats are swallowed up by the cap. As in all pneumatic guns using the inner barrel to hold the gun together the alloy muzzle holds the front bulkhead or ogive in place.

 

[popgun pete]

The X-ring works by allowing the slider rear end which has a chamfer on it to enter the first of the double seals without touching the sealing surface thereby allowing any water to escape before it enters the second sealing surface just as the full slider diameter hits the first one. The small annular ring of the water trapped in the gap can squeeze the X-ring radially and allows the slider to engage on both seals of the X-ring. Now hydraulic lock will stop further progress until loading the spear pushes the piston back and as the slider is already engaged on both seals of the X-ring it will then be sucked by the developing vacuum in the inner barrel to the full slider insertion position.

Note that the original muzzle had two X-rings separated by a gap, so this meant that muzzle suffered from hydraulic lock as the slider could not pass the front X-ring to reach the second X-ring without tipping water out first.

 

[popgun pete]

Here is the LG-Sub shaft tail, slider and stop ring. Note the chamfered rear end on the slider. When moving the slider on the shaft it needs to be wet or you can feel the sticky resistance of the inner "O" ring in the slider. How you get to the "O" ring in order to change it I have not figured out, but the gun came with a spare slider. In order to change sliders you need to unscrew the spear tail from the shaft and that is why it has a hole through it so can use a slim rod as a lever.

 

[popgun pete]

This new "Black Head" muzzle and nose cone is what I had been expecting on the original LG-SUB gun as hydraulic lock makes it near impossible to push sealed sliders into the muzzle unless you simultaneously move the piston back a little or tip some water out first or the vacuum cuff has a one-way valve action to let water out, but not in. All the rubber conical nozzle seal guns have this valve feature, which is the system used by the majority of pneumovacuum guns. LG-SUB needed an underwater loading capability, especially on their longer guns and now they have it for all of them with the new longitudinally ported muzzle using a ring of forward facing outlet ports just rearward of the muzzle nose.

The ports are radial, the longitudinal troughs turn out to be decorative, the ports being at the back end of each trough. The muzzle is rather short and contains one X-ring, not two as it had before. There is no ring valve, just a ring of ports at the entrance to the X-ring. A ring valve would need radial ports drilled in the alloy muzzle body behind the X-ring position, but as we can see there are none and the only feature is the screw thread to attach the nose cap or “black head” as they refer to it.

 

[tromic]

This is how it might work, X-ring in Black Head muzzle. It preserving vacuum using three lobs: upper and down on the left side and the upper on the right side, and facilitate water ejection using the upper left lob.

 

[popgun pete]

Being rubber the X-ring can distort and twist, even "O" rings distort under pressure, so I think this lets water out which is caught in the tiny gap between the sealing lobes of the X-ring during loading action. Once the pressure is static it just acts like an "O" ring when sitting on a uniform cylinder without any taper.

 

[tromic]

Being rubber the X-ring can distort and twist, even "O" rings distort under pressure, so I think this lets water out which is caught in the tiny gap between the sealing lobes of the X-ring during loading action. Once the pressure is static it just acts like an "O" ring when sitting on a uniform cylinder without any taper.

Yes, I made the textual explanation more clearer and changed word lips to lobs...

 

[popgun pete]

LG Sub now renamed as RG Spearfishing, the initials of Roberti Gianluca, founder of the company and designer of the guns.

 

[popgun pete]

I ordered a Black Head muzzle for the "Revolution" and it arrived yesterday along with two spare pistons and a seals kit. Once I have worked out how it functions I will post the results here.

 

[popgun pete]

Seeing as I already had the front end off I decided to take everything apart. Actually the Revolution and the Supreme which uses a similar back end are built like a Sten, only the materials are different with most of the LG Sub guns being machined in Delrin. Being coal black it was not the easiest gun to photograph the innards of. Quality is very good, which is what you are paying for. The rear body is machined in alloy, it will be the heaviest part of the gun.

 

[popgun pete]

After knocking the trigger pivot pin out and removing the trigger you can see how you can adjust the finger position by undoing a front grub screw and also adjust the trigger sensitivity at the rear. My advice is don't, unless you find you cannot manage it as is. I have never found a gun that I could not shoot straight out of the box.

 

[popgun pete]

The sear lever and rear inlet valve body are able to be more squeezed together in the back end of the gun because a metal rear body can reduce its longitudinal dimensions without losing any strength. Black anodizing makes it look like plastic, but it is an alloy component which has been elaborately machined. The see-saw sear lever is pretty much like the ones in all the Italian pneumatic guns.