Cleaning carbon of semi auto shotgun piston

Blackthunder

New member
Hi Guys. I have just purchased a new Fabarm shotgun. I have noticed that the gun deposits a lot of carbon on the piston. It especially does this on the front of the piston where the gas vent holes from the barrel are. This deposit seems to be rock hard and solvents do have much of an effect on it.
What is the best way of removing it? Brass brush? Any ideas would be more than welcome.

Here is a picture of the piston.

http://www.fabarm.com/en/hunting-shotguns-italy-exclusive-features-pulse-piston.htm

It has aluminium parts in it and plastic as well. So using very aggressive solvents might cause problems.
 
BOLT & GAS PISTON : The bolt and the gas piston as important components must be cleaned thoroughly. A good gun oil and bristle brush should clean it sufficiently.
Avoid over-lubrification. A thin coat of FABARM gun oil will help prevent rust.

That's from their owner's manual - for the XLR model.
 
Thank you. My manual is a flimsy copied leaflet in 5 different languages and hardly covers anything. I am still figuring out how to remove the bolt handle.
Fabarm makes quality products but their marketing / communications seem to be nonexistent.
 
DISASSEMBLY
Place the shotgun on safe and ensure that it is completely unloaded.1.
With the bolt closed, unscrew the forend cap 2. ( FIG.13a & 13b).
Then carefully remove the barrel. The gas piston slides off the front of the magazine cap shaft ( FIG.14 ).
Using the ring of an empty shell, carefully pry the cocking handle out and remove it as show 3. in FIG.15. Remove the action bar bolt group assembly ( FIG.16 ). Bolt, action bar and recoil spring being removed from the receiver by being slid down the magazine tube ( FIG.17 ).
With a pin punch tap out the two trigger guard pins 4. ( FIG.18 ).
The trigger group can be removed by pulling outward ( FIG.19 ).

That's from the page before - IIRC, it is page 5 in the XLR manual past the Italian language part
 
Thanks oneounceload. I own the SAT8, but the mechanism is the same. My manual also says that an empty shell can be used. But my gun dealer recommends a big screw driver with a block of wood under it to leverage it. He says that when these guns are new removing the bolt can be very stiff. I am not sure if that is really a great idea. Do you find that the bolt comes out easily?
 
I do not own one, but I have had an 1100 and I do own a Beretta A400 - now and again, the 1100 liked to "throw" the bolt into the grass - I learned to tie a bright orange piece of survey tape to it so I could find it - therefore, a loose bolt would be a bad thing.

Most of these modern gas guns really don't need much take down for cleaning any more - they are pretty amazing in that regard; whereas that 1100 needed a cleaning every 150 rounds or it would slow down and jam up from buildup.
 
I have a 390, and perhaps I'm cleaning it too much, but I clean the piston and the barrel after each outing (150ish rounds). I was told that using solvents on the piston components may leave a residue and more building up and sticking. As a result, I've been using 0000 steel wool on the piston components. It takes about the same amount of time as when I used Hoppes.
 
No, you're not cleaning it too much ( there is no such thing ) ....cleaning it after each outing keeps that carbon buildup to a minimum.

I doubt there is any real evidence that solvents will make carbon buildup any worse.../ and I'm of the school that says - after you use any solvent - you must oil the gun / most any light oil for lube should be fine ...Rem Oil, Break Free, whatever you want to use...

I don't own any gas guns these days / the semi-autos I have are all Benelli's so they're Inertia guns ....but today's gas guns certainly seem to shoot cleaner than they did 3 or 4 generations ago ...but I'd still clean them every 250 - 300 shells / or every range trip if they were mine.
 
For stubborn deposits, I've found that Shooter's Choice brand solvent works well. The secret, with any gun cleaner, is giving the solvent some time to work, too many shooters expect cleaners to work instantly. Of course, something designed for cleaning metal may not favor wood nor plastic.
 
A solvent should not leave a residue - it should be removing it. WD-40 will, after a time, start to leave a "varnish" like residue.

I use Shooter's Choice as well and have used brake cleaner (REALLY works - BUT will eat your plastic and damage your wood - so I only use it on the inside of barrels to get wad plastic out and on choke tubes.

As Jim said - no matter what solvent, re lube the gun with grease or oil where appropriate
 
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