Alert to Dry or Vacuum Barrel kit users

[popgun pete]

Anyone who has fitted a dry or vacuum barrel kit to their pneumatic gun and not greased the muzzle connecting screw threads on the front of the inner barrel tube while doing so should rectify this situation as soon as is practical for them to carry out. Without grease between the screw threads saltwater can gradually wick in along the tiny gaps between the thread forms and start up corrosion which in the long term will essentially weld the muzzle onto the inner barrel tube. Then you will have great difficulty in removing the muzzle and can cause the inner barrel tube to rotate inside the gun which can break and bend things internally if you persist in trying to undo it from the front end. Greasing the screw threads will avoid this happening, however gun dismantlers sometimes wipe the screw threads clean and then put the gun back together without considering the future implications. In the old days an anti-seize compound in the form of a thin white fluid coated the screw threads, in later times a clear grease is used, probably silicone grease. I use a lithium based grease (Valvoline X-All), but any grease is better than nothing.

Having with great difficulty unscrewed seized muzzles from inner barrels I suggest that avoidance of the problem is far better than the cure.

 

[Gazz]

Thanks Pete,

I use that white oring grease. Also i use nylon tovarich kits so welding would be unlikley.

also the Cyranos (and i am assuming sten 11s) have a few internal upgrades in the latest models. Including a notch in the back of the inner barrel and section in the handle that locks the inner barrel and stops it from rotating (like the asso) makes life much easier!! Also the upgraded trigger is a stroke of genius.

 

[vasile]

Anyone who has fitted a dry or vacuum barrel kit to their pneumatic gun and not greased the muzzle connecting screw threads on the front of the inner barrel tube while doing so should rectify this situation as soon as is practical for them to carry out. Without grease between the screw threads saltwater can gradually wick in along the tiny gaps between the thread forms and start up corrosion which in the long term will essentially weld the muzzle onto the inner barrel tube. Then you will have great difficulty in removing the muzzle and can cause the inner barrel tube to rotate inside the gun which can break and bend things internally if you persist in trying to undo it from the front end. Greasing the screw threads will avoid this happening, however gun dismantlers sometimes wipe the screw threads clean and then put the gun back together without considering the future implications. In the old days an anti-seize compound in the form of a thin white fluid coated the screw threads, in later times a clear grease is used, probably silicone grease. I use a lithium based grease (Valvoline X-All), but any grease is better than nothing.

Having with great difficulty unscrewed seized muzzles from inner barrels I suggest that avoidance of the problem is far better than the cure.

Thank you very much Pete..

 

[popgun pete]

Thanks Pete,

I use that white oring grease. Also i use nylon tovarich kits so welding would be unlikley.

also the Cyranos (and i am assuming sten 11s) have a few internal upgrades in the latest models. Including a notch in the back of the inner barrel and section in the handle that locks the inner barrel and stops it from rotating (like the asso) makes life much easier!! Also the upgraded trigger is a stroke of genius.

Yes, the risk of rotating the inner barrel has been minimized with larger indexing pegs on the rear of the inner barrel and inside the grip interior, but if the muzzle seizes onto the inner barrel threads then it is virtually impossible to remove it with the inner barrel still installed in the gun. Even after you pull the gun apart working from the rear end it is still desirable to loosen up the muzzle for future maintenance and inspections. I found that with a special tool (two large bolts and a thick steel collar that surrounds and pins the muzzle via the muzzle relief ports) that the muzzle could be wound off the seized threads with the inner barrel tube firmly locked into my lathe, but the barrel usually turned in the jaws of the chuck (no matter how tight they were) and marked the outer surface while doing so. Although no seals sit in that section of the inner barrel tube new seals often have to be slid over it so that it was necessary to take a "clean up" cut and slightly reduce the OD of the affected barrel section. If a muzzle is well and truly seized on then you have to machine the muzzle off the inner barrel and hope that the screw threads underneath are still OK for attaching a new muzzle. Hopefully no one ever uses "Silastic" or other self-curing silicone rubber on the muzzle threads as it resists the strongest efforts without budging a millimetre, you will destroy the parts first! Misguided users have resorted to this stuff to stop leaks when they failed to understand where the rubber seals are located. Then the old muzzle has to be machined away.

As for plastic muzzles, well they will not seize, but they are not as strong as aluminium muzzles, however some guns have used them going back over a long time period. I was told that the Mordem "Saturno" had a plastic muzzle, it was something like a "Sten" in being a rear handle gun, but I have never examined one and have only looked at the parts diagram and a few photos. A while back we saw the Mares "Sten" muzzle in plastic with three relief ports, but they seemed to have only a limited production run before returning to the familiar metal muzzles.

The absence of relief ports will make a plastic muzzle stronger and I guess that is why they are used in the vacuum barrel kits from some manufacturers. Personally I prefer metal muzzles as the muzzle threads are unlikely to strip out if the screw threads are not damaged.

 

[tromic]

After removing the handle, I use a tool like this on a picture (A1), made ​​in wood, to unscrew the muzzle. The tool is fasten in a vice, on a barrel, where comes the handle.