• Welcome to the DeeperBlue.com Forums, the largest online community dedicated to Freediving, Scuba Diving and Spearfishing. To gain full access to the DeeperBlue.com Forums you must register for a free account. As a registered member you will be able to:

    • Join over 44,280+ fellow diving enthusiasts from around the world on this forum
    • Participate in and browse from over 516,210+ posts.
    • Communicate privately with other divers from around the world.
    • Post your own photos or view from 7,441+ user submitted images.
    • All this and much more...

    You can gain access to all this absolutely free when you register for an account, so sign up today!

LGsub Minaru Revolution X-Ring dimensions

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.

FlotsamBob

Member
Dec 28, 2022
33
7
23
38
Good day,

I have purchased a (functioning I hope). LGsub from 2018 in 102cm guise. Unfortunately the previous owner lied about its usage history, seems to have been using it with a 7mm Pelengas spear and slider whilst leaving the original spear and slider barely used...

The gun is devoid of the two seals in the muzzle head, slider still has one on the OG spear. Anyone here know the dimensions of the two X-Rings (maybe the slider as well?) in this model?

Cheers!
 

Attachments

  • IMG_20240628_102816.jpg
    203.8 KB · Views: 107
  • Screenshot_20240628-104152~2.png
    965.7 KB · Views: 108
Maybe have a look here.

New LG

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...
forums.deeperblue.com
 
Reactions: FlotsamBob
Great write up. I can likely figure out what their sizes could be myself for sure. Luckily the creator has some spares in stock for this model and is willing to send them. Unfortunately the piston seems rather scratched at the tip, probably from badly located spear slider during insertion. Will se if they polish out on a lathe. I'll try take some pictures of the inner barrel and maybe you can help me decide if this gun is toast?
 

Attachments

  • IMG_20240628_145919.jpg
    628.2 KB · Views: 91
The scratches in the piston tip don't matter as long as there is no grit embedded in them. Hopefully sand has not been in the gun. The first version of the Revolution gun is a Mamba system with a sealed slider and muzzle creating two seals. A spear lifted from the sandy bottom after a shot needs to go in with no sand on it and the use of any grease on these parts that causes sand to stick will be bad news. A previous owner may not have known that. The barrel may not be scratched, but it pays to shine a light down it and check it out.
 
Thanks Pete. Fully checked out and passed the torch test. Scratches on piston tip were being caused by a nick in the tip of the barrel, slicing into the piston as it reached the brake. Filed and smoothed it down and I think this rifle is good for the water. Will try some regular o-rings whilst I wait for new x-rings. Would you happen to have a Salvimar 11mm Vuoto muzzle in stock you could measure the thread pitch and diameter on? There is mention of it fitting the 12mm barrel of LG sub rifles here with no resolution: https://pescasubapnea.forumfree.it/?t=78689866&st=30 ...
 
I don't have a Salvimar vacuum muzzle for 11 mm, but I can check an 11 mm muzzle from a Cyrano on the RG Sub barrel. Due to a parting of the ways with the founders LG Sub is now called RG Sub. The Revolution guns are 12 mm inner diameter, but the OD of the inner barrel will be the deciding factor as that determines the thread size used. Pelengas use 12 mm inner barrels, don't know if they fit. From memory they made muzzles for other guns, but since comrade Putin embarked on his invasion I don't know if the factory is still in business. I know they moved the machinery to get away from the combat zones.
 
Here is a Cyrano muzzle on an LG-Sub Revolution, so it just screws on and the threads do match, however the rear of the muzzle is too big to go inside the socket nose of the Revolution nose cone. A fix would be to machine the rear of the alloy muzzle down, however this may already be done on the Salvimar 11 mm barrel vacuum muzzle, but the diameter would need to be checked.

Note the inner barrel is anodized black. most pneumatic guns just clear anodize their inner barrels.
 
Last edited:
Well here is a photo of the Evo replacement muzzle from Salvimar and that rear dimension is provided.

P.S. Just checked the diameter of the Revolution socket and it is 20 mm, so the rear of the Salvimar muzzle will go in the hole, how far in I cannot tell, but if too long a bush or thick washer may suffice to adjust it. The Revolution muzzle piece is very light and the Salvimar would certainly be heavier.

Personally I would not use a different muzzle even if something else fits, the guns have been designed around that sealed slider system.

I ordered a Black Head muzzle for my Revolution which came out with the original muzzle that requires water to be tipped out to get the Mamba style slider started as a hydraulic lock can occur between the two X rings. Just exactly how that new Black Head muzzle works I don't know as you need a blow-off valve somewhere. On the rubber nozzle seal vacuum guns the skirt of the nozzle can expand and let water out, but not in, that is why it is designed that way, so it is its own blow-off valve. On the LG they may have just vented the space between the two X rings, I will not know until I get my hands on one.
 
Last edited:
Reactions: FlotsamBob
Fantastic info!

I'm keen to keep all my guns similar in parts so as to not diversify the spares. This may be the ideal low cost solution. I think I can lighten the Salvimar nozzle by cutting down the outer slider ring rest (for 7.5 - 8mm spears?) if the 11mm version has one. Also machining some lightening grooves in the outer muzzle head body could be beneficial.
 
I read the old style LG muzzles have a proclivity towards spitting out their seals if loaded incorrectly, or the spear depressed in one smooth movement. Makes sense how mine lost its originals early on. As this will be my wifes gun I'd prefer the seemingly more rugged offering from Salvi.
 
Well you cannot always believe what you read, there could be a number of reasons why they were missing, they may even have been removed as you said the spear and its slider appear unused. The thing to get right with vacuum guns is to get the spear started in the muzzle and aligned before you begin pushing. A hydraulic lock occurring early can stop that happening. On the Taimen guns, which were one of the first mass produced vacuum barrel guns, they achieved that alignment with the spear slider plugging into the muzzle so when you pushed on the spear it was already lined up. A number of European guns just rely on the stop ring in the muzzle entrance step and that does not necessarily guarantee everything is lined up. A lot of spearguns used the shaft tail stop diameter to line up in the gun using the shock absorber bore, but that is behind the vacuum seal, so it relies on pushing the shaft in holding it near the shaft tail end and then reaching forward for loading the shaft. Another gun using the slider as an aligning plug is the Pelengas. Recently Salvimar made some better sliders, but they still don't plug into the muzzle. For this to work the sliders also need hydrobrakes to swallow some of the shaft tail stop diameter and reach back into the muzzle.

My guess is the hydraulic lock if you don't tip water out of the Revolution muzzle makes the gun hard to get aligned, especially on a longer gun. If you remove the front X ring then the front end of the muzzle creates a better plug holder for the slider which can go in further without any lock. It will only start a hydraulic lock at the rear and now only X ring and that provides a better aligning action on the shaft. I think the Black Head muzzle only has one X ring, but will confirm when I get one. Another way to change the original muzzle would be to drill radial holes in the muzzle between the X rings reducing the first X ring to just a guide element.
 
Last edited:
Interesting stuff.
Keen to give those new Salvi sliders a try although I haven't had trouble with their old style. The LG (RGsub) owner has gone silent on me despite offering the O-rings initially. I respect that he's probably on holiday but such ghosting requires moving my business elsewhere in future. Pity as I quite liked his reel designs and had considered their new pneumatic models if I was to enjoy my current one. I'll have a go at figuring out the X-Ring sizes in this muzzle, otherwise a new Salvi Vacuum muzzle is a rather cheap and effective alternative.
 
You could always switch to the Black Head muzzle for that gun which was redesigned in order to allow muzzle loading without first tipping water that sits just in front of the piston out of the front end of the gun. This is done by holding the gun momentarily above the surface to seat the sealed slider in the muzzle entrance, then lowering the gun back into the water to complete spear loading with the hand loader.
 
Thanks! Yes I had considered that, but the prices are dissuading to say the least. The fact that the owner doesn't care about helping people out unless they're willing to part with loads of money (I had also asked for a quote for new piston, left handed handle and 7mm slider and then gratefully declined when given the price) is another factor in my not wanting to sink any more money into this company... My budget guns do the job splendidly, I had really just wanted to figure out the hype behind these high priced "artifacts".
 
The parts are expensive because every item is machined from stock, either rod or bar stock. Whether that justifies the purchase price is hard to say, but certainly the parts prices are high. With injection moulding you have the high initial die costs and then the parts can be pumped out relatively cheaply and quickly. The longer the production runs, then the better it is as you cover the set up costs and then start making a profit. Machined parts you have the machining time and the off cuts which may be recyclable, but it is going to be more costly, however changes can be made to the product by altering the cutting program, you don't have any dies to modify or replace. How much did you pay for that gun second-hand, as a ballpark figure, and what extras came with it? I have ordered some parts, but have yet to receive them. More about that when they finally arrive.
 
Sure I understand that. With all the new bits and some import tax I would be better off buying a new LG gun - even a 2024 model mainstream brand pneumatic gun would have cost the same as old stock parts. The used LG gun I purchased came in at 210 AUD after I requested a partial refund for dishonesty. The reel and spears were worth the price I figured.

Any chance I could persuade you to pull out an X-Ring from your old muzzle and measure it? There apparently used to be a video of the LG owner explaining the parts numbers for all the seals but he has since taken it down... Otherwise I have a Salvimar vuoto muzzle already in an online store basket, just trying to figure out what else I'll need for my big freezer filling fishing trip this August.
 
Last edited:
I can tell you now those X rings will not have blown out as they are very hard to dig out without ruining the ring or scratching the seating groove inside the muzzle. I have actually got the front one out with an awl that eventually pierced the ring, so unless these seals are worn out I suggest gun owners don't try to remove them. If the rings are toast then it doesn't matter. I am no amateur at this, but it took a lot of wiggling to even get under the seal to lever it up. Measurements later. The only reason I persisted is I am not going to use this muzzle.
 
Here are photos of the front X ring with one shot taken at a slight angle to show the ring periphery. Because the rings have been sitting in the grooves for years they may have been squashed slightly and may expand after being out for a while. Vernier calipers show ID is 10.3 mm, OD is 16.1 mm and section width taken perpendicular and parallel to the ring axis give 2.54 mm and 2.59 mm respectively. White specs are probably dried lubricant from when they were installed in the muzzle. I noted the LG Sub gun had not a speck of grease in it as it had been assembled only with oil. Nothing on the muzzle screw threads for that matter, just oil.
 
Reactions: FlotsamBob
Excellent thanks! This will help a lot of other people struggling with the same issue. I suppose poor handling of my gun caused the seals to get damaged and eventually blow out. Unless the previous owner just dug them out to better exhaust the now wet barrel when using the Pelengas line slider... We'll never know, either way he was definitely a bit dishonest selling a "barely used" gun. I ordered a Salvimar nozzle before I saw your reply so will be interesting to note any major weight differences affecting the balance of the gun. I will design and 3d print a better seating guide to fit the slider on the 6.5mm (lg slider with removed o-ring) and 7mm (pelengas slider, same diameter as LG) spears and glue them into the salvi muzzle.
 
It is possible the original owner of the gun wanted a heavier shaft than the 6.5 mm shaft that the Revolution gun came with. Using the gun with a 7 mm shaft would flood the barrel as it would have lacked a sealed slider and would slow the shot and possibly the water being ejected from the inner barrel peeled the two X rings out, but I doubt it. Difficulty with loading due to hydraulic lock on the slider without tipping the water out first could have been another turn off. The simplest solution in that case is to take the front X ring out and rely on the rear one instead. Being a longer gun the heavier muzzle has more tank length to offset the weight through its greater buoyancy. A short gun would be more affected as the tank is much smaller, hence less buoyancy.

No sign yet of my spare parts from RG Sub, previously LG Sub, which is a bit of a concern as I paid a small fortune for them.
 
Last edited:
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…