I have a synthetic stock on my Sako A1, but I don't know the manufacturer. I am hoping it is a McM. How can I tell? I looks like it has been painted blk, looks like some green and reddish colors are trying to come out, It has a pachmayr recoil pad

I bought the rifle used and the owner wasn't sure/didn't know

Checkering pattern looks like it may be a Rimrock. Sure way to tell that would be the profile of the forend tip, they were very rounded. Just a guess.

I'm no expert, but that's kinda what I was thinking. Rimrock was a nice product.

its not a rimrock

What obvious tell let’s us know that it isn’t a Rimrock? Genuinely curious

The latter Rimrocks by Jim Borden were absolute junk. He continued to build and market them after his mold wore out. And would not honor his pos product warranty.

The checkering, grip cap, and nose of the comb is different on that stock from any Rimrock I have seen - but I will be the first to admit I have never seen one (rimrock) inlet for a sako.

Looks like a McMillan.....

The grip cap, and checkering pattern looks like it was molded off a factory ruger.