James is right, It's stainless. The grip frame on my MK IV competition matches my upper exactly. Nice heave rimfire. (If you found this answer helpful, please mark it as the "Best Answer". Thank you.)

The UPC (universal product code) from Ruger says that this is the "Stainless" frame pistol. Other vendors with the same UPC list it as "Stainless" as well. You can call Buds Customer Service at 859-368-0371 to verify but this is "Stainless" according to Ruger. - ruger-firearms.com/products/markIVCompetition/models.html