FN-49 and corrosive ammo

[Jordan A.]

Hi Guys, I have a beautiful Egyptian FN49. My question is if I shoot corrosive ammo, do I have to disassemble the rifle to clean out the gas tube? I have plenty of old bolt action mil surps and I know how to clean the barrels out but this is my first semi-auto. Do the corrosive salts from the primer make it 20 inches down the barrel and into the gas hole?
I think in the future, since this gun is pretty valuable, I am only going to shoot new ammo depending on what you guys think, Thanks, Jordan

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[browningautorifle]

You'd be surprised how penetrative corrosive salts are. You'll need a comprehensive cleaning after firing, and not too long. Depends on just who made the ammo, how long before rust starts.

[Bruce_in_Oz]

The gas plug and piston were originally hard-chromed for all FN-49 production. Barrels were NOT. Treat ALL ammo, especially "surplus" ammo as CORROSIVE and EROSIVE; your guns will last a LOT longer.

The gas system should be stripped and cleaned after EVERY firing, whether the ammo is known to be corrosive or not. The fouling left by even "non-corrosive" ammo will start to "sludge up" the system fairly quickly, especially if you live anywhere that gets a bit humid.

NEVER use anything abrasive to clean the carbon fouling off, as (especially) "Scotchbrites" etc., contain little particles of Silicon Carbide that will not only remove the Carbon/jacket fouling, but will also hack away at the chrome plating, thus reducing the corrosion resistance and the closeness of the gas seal. If the piston and plug look particularly disgusting, put them in a container of "Carburettor Cleaner" overnight and don't smoke or light a fire near that stuff. The threaded regulator collar needs to be wound back and the thread cleaned and LIGHTLY lubed from time to time as well. This requires removal of the top handguards.