M14 Forum banner

Unusual gas piston fouling

1006 14
I was home this weekend for a three-gun match and was inspecting my post-ban loaded M1A. I was checking it over and got to the gas piston check, to see if it would move freely. Wouldnt budge, I pulled the gas plug and looked into the cylinder, it was caked with carbon fouling, I couldnt beleive it. The last time I shot it I sighted in a scope on it and didnt put but maybe forty rounds through it. I cleaned it out and put it back in but I havent ever had this happen with the Portugese ammo I shoot.
Any one have any ideas?
RRVI
1 - 15 of 15 Posts

·
Banned
Joined
·
254 Posts
that is rare. I shot Port ammo for a year with my SA M1A and only cleaned the external part of the piston. Never had a problem. When I was in Viet Nan we almost never removed the plug and cleaned the piston. Never had a problem there eather and that was with lots of shooting................SP/4 Twiggy
 

·
Registered
Joined
·
49 Posts
Piston fouling

I have the same thing happen with both my M1As when shooting port or hirt or anything really. If I do not clean my piston and cylinder out right after Im done shooting, within a weeks time they will be frozen up with rust. I have to tap them out with a drift. I made things a little better by polishing the pistons but it will still happen. :oops: The valve will get stuck as well. Dont have much trouble with carbon buildup though.
 

·
Registered
Joined
·
121 Posts
I also had the same thing happening. what I was doing wrong is cleaning my M1A sitting on the bipod. all the solvents got into my gas cylinder and mucked things up. this was a few years back when I first bought the rifle. I learned fast to clean my baby upside down.
don't know if that is the case here but I thought to put my two cents in.
rooster
 

·
Banned
Joined
·
254 Posts
rooster33 you may have the answer because I clean my bore upside down and never in the upright position. I know port ammo isen't corrosive so it must be something in the way the rifle is being treated.
..........SP/4 Twiggy
 

·
Registered
Joined
·
130 Posts
Rooster does have the right answer. Oil and solvents cause a nasty mix with carbon and powder residue which muck up the piston & cyl.

Invert for cleaning. When I clean, the rifle comes out of the stock, as it should. More nasty lack of maintenance issues arise due to the myth that the rifle should never come out of the stock!
 

·
Registered
Joined
·
121 Posts
Papafoxtrot,
I clean mine inverted, and evry so offten it comes out of the stock, say about evry 500 rounds or so. mine is in a USGI fiberglass stock and it is not glass beded, never had a problem taking it out and putting back in, the zero never changes.
one more thin when cleaning, the gas piston must be absolutley dry.
rooster
 

·
Registered
Joined
·
121 Posts
Papafoxtrot,
I clean mine inverted, and every so often it comes out of the stock, say about every 500 rounds or so. mine is in a USGI fibreglass stock and it is not glass bedded, never had a problem taking it out and putting back in, the zero never changes.
one more thin when cleaning, the gas piston must be absolutely dry.
rooster
 

·
Registered
Joined
·
121 Posts
Papafoxtrot,
I clean mine inverted, and every so often it comes out of the stock, say about every 500 rounds or so. mine is in a USGI fibreglass stock and it is not glass bedded, never had a problem taking it out and putting back in, the zero never changes.
one more thin when cleaning, the gas piston must be absolutely dry.
rooster
 

·
Banned
Joined
·
572 Posts
I just close the spindle valve. My piston stays dry. And I leave the hoppes soaking in there for days sometimes.
Also I shoot or at least carry mine almost every weekend rain or shine. I have noticed that shooting in the rain the piston fouling gets really gummy. I don't know if that is part of your problem but thought it worth mentioning. It always works just fine though even when it won't slide freely. I never cleaned my piston in the navy either unless I had a match to go to. Rarely. I clean it every 300-500 rounds now.
 
1 - 15 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top