Anyone had problems with corrosion around the gas ports. I have shot my 556 very little. I use factory, non-corrosive ammo, and yes, I clean my rifle after shooting it. It has been a few months after my last shooting/cleaning session. Upon stripping the rifle down, I observed that it has corrosion in the lower inside part of the ring through which the gas tube passes. It is corroded around the ports. There is discoloration (not carbon buildup) on the bottom of the gas tube where it lines up with the ports as well. I only use a cotton cleaning patch and Break Free in this area. I have always wiped this area clean before reassembly. I also observed some discoloration on the top of the barrel where it comes out of the front of the gas block. This is directly below the knurled ring on the gas tube. This is frustrating to see this. There is no corrosion anywhere else. I use this ammo/cleaning combination with other rifles and have had no problems. I do take care of my firearms. This is not from any neglect. I would really like to know if anyone else has had a similar issue. I've yet to contact Sig about this, but I will. Thanks in advance for any feedback.

Is there any way you can post a few HR photos of the area(s) in question?

...are you sure it's corrosion? ...it may be residue from the constituents in the byproducts of combustion...this residue may "sometimes" appear as rust...try using some bore cleaner and a nylon brush to remove it...and see what happens...



...this "heat staining" is perfectly normal...especially around the ports in the gas valve...nothing to worry about...




...this may be a little residue from gas escaping in that area...try the nylon brush and bore cleaner...and see what happens...this is not a biggie...


...you should wipe down all metalic surfaces with Breakfree CLP after cleaning...including leaving a "very very thin" film on the gas system components...including the areas you mentioned...

...pictures would be helpful...if you could post some...it's difficult when not having the gun in front of you to give you a definitive response...

when you shoot any ammo the heat drys out /evaporates the oils but with Mobil one /castrol synthetic motor oil-15w50 stays better its work great with ar-15's and others as well but it smells like burned tires .....the other is not to bad is gunzzlia it has its uses too

Yes, try letting some solvent sit for 5 minutes to penetrate, then try scrubbing with a plastic bristled brush. I had what appeared to be corrosion but it was actually just carbon build up. I use a gel version of Mpro7 for items like that.

I've also had good success on small parts like the gas valve with Slip 2000's "Carbon Cutter".