Lewis Gun disassembly

[ranger1385]

I am attempting to remove the receiver from the barrel/jacket for cleaning purposes and because I bought a new barrel to install in the future.  The weapon looks like it was seldom cleaned by the previous owner.  I am having a real hard time removing it.  I watched a couple of videos and removed the pin and soaked in oil before hand.   Whacked it with a rubber mallet ant it moves like maybe a 1/4 inch.    Reluctant to apply heat because of the aluminum radiator.  Anyone have any tips? Thank you.  

[1gewehr]

I usually remove the gas plug so that I can remove the radiator cover.  That will let you see what's binding.  It also gives you more room for whacking!  I've seen a gun that had the gas tube partially unscrewed and that caused the receiver parts to bind like you are seeing. With the radiator cover off, you'll be able to see that.  You might have to remove the radiator to get things back into alignment.  That might take some heat.

Mine likes to be tapped with a hard rubber hammer a few times if it's been a while since I last had it apart.  I use Ballistol for cleaning as it seems to make cleaning and disassembly easier the next time.

[ranger1385]

Thank you!  Definitely could be the gas tube.  It wiggles around a little.  Will see if moving that makes it easier.  

[DougStump]

If you haven't yet, you must remove the Gas Regulator.  You can also remove the Front Radiator Casing and the Clamp Ring.  The Rear Radiator Casing can not be removed yet as it slides off the back of the barrel.  

The majority of British Lewis Guns in the US were from a single shipment of some 500 that International Armament Corp bought from Ireland back in 1959.  The deactivation procedure was to take a stick welder through the ejection port and tack weld the back of the barrel to the inside of the receiver on the left side, weld the chamber shut, and grind off the face of the bolt (this complied with the existing laws, but also made reactivation easier).  As the gun in new to you, before you apply a force to unscrew the barrel, I suggest you inspect the back of the barrel and receiver carefully to make sure this weld has been removed.  Sometimes they did a "better" job creating enough heat to discolor the bluing on outside of the receiver.  Other guns had minimal welding, I can barely see the evidence inside my receiver.  It's possible the weld was so poorly done that the chamber was left intact but the barrel is welded to the receiver.  Check the back of the barrel with a strong light look for any remaining weld.  Admittedly, this is a long shot, but something to eliminate.  

Drown the outside of the barrel and receiver joint with Kroil and let it sit. 

You may have trouble unscrewing the Gas Cylinder.  The manual says to use the Piston Rod, but mine refused to come loose.  I made a special wrench to pop it loose.

(I hope this makes sense, I've only had one cup of coffee so far this morning)

Doug

[Lewisfan]

Maybe a dumb comment - but make sure that the pin is removed. Talking about the one that slides into place holding the shroud and receiver together.  Take off clockspring assembly to access. 

Like I said - likely a dumb comment, unless you forgot to pull out the pin...  Good luck!

[ranger1385]

Finally got it disassembled today.   Had years of rust, dirt and oil built up in the threads.  

[MGMike]

2 hours ago, ranger1385 said:

Finally got it disassembled today.   Had years of rust, dirt and oil built up in the threads.  

I love happy endings!

M

[APEXgunparts]

You will need the screw jack tool with its separate collar to extract the barrel from the aluminum radiator.
There are copies of the originals and SkyCrest Armory makes a modern version in Delrin.

Richard

[Lewisfan]

Or drop the muzzle end with cup onto a 2x4 (or similar wood surface) to separate the barrel from the radiator.  I slightly unscrewed the cup to give the barrel room to move.  Worked fine on several different Lewis guns over the years.  Have never seen a screw jack tool in person.  Not arguing that it is the right tool, just sharing what I did to make it work.

Make sure to remove the gas nipple!

[ranger1385]

I was wondering about the gas (sleeve) on the barrel?  Does that just slide off?  Additionally, after I cleaned the weapon, I noticed there was a fair amount of play in the gas tube and regulator.  Is that normal?   It was very tight, when I disassembled it because of years of carbon accumulation.  

[DougStump]

The Barrel Band does slide off, but it might need some "encouragement".  I would suggest using a Crescent wrench adjusted to just touch the barrel above the band, then apply a dead blow hammer to the side of the wrench.  As the barrel is tapered, you won't have to use much force before it comes loose.  You might want to mark one side of the band before you take it off as it's tapered to match the barrel. 

[DougStump]

I'm just going to throw this in here instead of starting a new thread.  I noticed that when firing reloads, I could feed a "thump" before the "bang".  I finally figured out that the shoulder of the cartridge was hitting the top edge of the barrel.  Most reloading dies do not size the shoulder back to the original (WWI) dimensions.  There is a bump on the bottom of the Feed Arm that's supposed to start the cartridge down into the chamber, but with the larger shoulder on the cartridge it wasn't enough.  I thought about brazing the bump higher, but with my luck I'd probably warp the arm.  Hmm.  Ya know the stainless steel adhesive tape they use on air conditioning ducts (we called it 1,000 mph tape in the Air Force)?  I put two layers over the original bump, that solved the problem and doesn't interfere with the operation of the gun.   And it's easily removable.  Now the gun runs as smooth as silk (as long as the Return Spring is adjusted correctly). 

[ranger1385]

Yeah, that AC duct tape is pretty strong.  Thanks for the advice.