Haven't seen any Sig info. Don't really wish to remove barrel as this would require re-sighting in. I use the MPX in PCC class of 3 Gun so it gets a lot of use. I have NOT had any operation problems.

I would say not. Unless you get a failure, i wouldnt mess with it. I may just be an idiot, but i buggered up the gas ring when i was swapping barrels. I have the gun running now so im going to leave well enough alone.

I cleaned mine at about 5000 rounds, though it was still operating fine.
I had a massive carbon build up on both the piston face and the gas port. The gas port was almost blocked. Took a lot of soaking, brushing and picking to clean it up. I now clean it much more regularly. I have not noticed any discernable shift in POI after removing the barrel from either my 8" SBR or my 4.5" pistol.

MeatMan: Thanks for the info! Did you re-install the barrel and use a torque wrench? I ask because my 1/2" drive torque wrench won't do the job!

I do use a torque wrench to secure the two bolts holding the barrel to the amount they suggest in the MPX manual. Odd that your 1/2" drive won't do the job. I can't remember the torque rating off hand, but I don't remember it being anything too high.

A 1/2" drive is for torquing such as head bolts on cars and is not very accurate for small bolts torqued in inch pounds.

Makes sense now smokey. I have a smaller inch pound torque wrench that I use for this type of thing. It has been so long since I worked on my cars, I think my old ft-lb torque wrench is probably in my son's hands now.