Thanks Dennis, I tend to agree with you. However, I bought the rifle used (a high end action) which had the Sako assembly already installed. I'm kind of stuck. In reality, I believe the spring to be weak, as the case gets knocked off the extractor when it is pulled out of the chamber and gets to the point where it is almost out of the action - the mouth of the case strikes the front edge of the loading port and out comes the rim from the claw. Very annoying.
I just thought that if I could find a new assembly, I would at least have a spare claw if the claw wasn't, in fact, the problem. When I get home from work on Thursday, I'll measure mine and get back to you - seems PTG's, at least, are a bit narrower than others.
Rooster