M1A - Gas Pistol Corrosion/Erosion Question

[Carnitas]

I noticed some pitting at the end of the gas piston on my M1A. I've photographed it in the attached picture. Other than the bit seen in the photo the rest of the piston looks fine. Any idea what's caused this?

 

[Sheldon]

Is that a g.i part or one of the newer cast ones made by the current Springfield Armory?? Possibly corrosion from shooting corrosive ammo and not cleaning properly afterward??

 

[TODD3465]

To me from what I can tell by the picture in question. It looks like rust pitting that has been blown over by continued firing.

And I'd hazard a guess it was from corrosive ammo residue.

Though I won't rule out poor QC.

 

[Vern Humphrey]

It may be a sub-standard piston, but I really think it's an ammo issue. Polish it carefully, using a cloth and solvent, then check your ammo.

 

[Phoenix_III]

Corrosive Ammo vote? Gun is new? What have you been feeding it? Surplus? Not all 'non-corrosive' surplus is actually non-corrosive, it's just slower!

 

[Vern Humphrey]

Corrosive Ammo vote? Gun is new? What have you been feeding it? Surplus? Not all 'non-corrosive' surplus is actually non-corrosive, it's just slower!

One thing to do is pull a bullet, dump the powder, and chamber the primed case. Hold the muzzle about an inch from a mild steel plate (even the lid of a steel coffee can will do) and pull the trigger. Leave the target lying outside for a night or two and check it for rust.

 

[Carnitas]

I assume its recent Springfield production; everything else on the gun is.

All the ammo I've shot in it has been RadwayGreen Surplus, Port Surplus, Aussie Surplus, and a couple boxes of modern Rem/Fed ammo.

I'm skeptical of the corrosive ammo theory since there isnt more corrosion. If I turned that piston 180 degrees and took another picture, or if I took a picture of any other part of the piston, you'd be looking at a "normal" looking pistol. Its pretty localized.

Fortunately there are high quality aftermarket pistons available for not much money. I've heard good things about the Sadlak NM Piston and its only $44.

 

[Sheldon]

If it is a cast part, it may just be a badly cast one. Springfield has a lifetime warranty on it so I would at least let them know and try to get a replacement. They may send a g.i. replacement if you're lucky and if not the cast part replacement can be an emergency backup.

 

[Carnitas]

The problem w/ springfield life time warranty is that they want the entire gun back....literally, lock stock and barell. That means you get to go by a hard case, a box to go over that, spend a bunch of time packing it up, risk loosing it to a dirty UPS employee, wait who know's how long for Springfield to finish, run the UPS gauntlet again. If you're lucky springfield will reimburse you for your shipping costs but none of the other stuff.

Its cheeper to just buy a new piston.

 

[Matthew748]

I would contact Springfield before buying a new piston. I called them about a bolt related problem with my M1A a little over a year ago and they gave me the option of shipping back either the whole rifle or just the bolt assembly.

 

[Fingolfin]

Looks like either horrible pitting, or air pockets in the casting. I would lean toward casting defect if the gun is new, and the barrel looks ok.

 

[Carnitas]

This gun ejected its bolt parts a couple months ago at a match. I practically begged the Springfield rep to let me just send the bolt back for a rebuild, then I begged him to just send me the parts and I'd rebuild myself. "Nope" he said, they need the whole rifle back on all repairs so the can make sure its safe and testfire it.

Again, I ended up buying the parts and fixing it myself....at least I got better quality parts than they would have put in it.