Good question. On my new PPK, when I removed the recoil spring for cleaning, it left a slight scratch on the barrel. Thanks for asking this question; it'll be interesting to see how the more experienced folks weigh in on this subject.
I noticed that when the recoil spring is removed that it scratches the barrel apon reinstallation..
I sanded that sharp edge from the inside of my spring but left it still tight on the barrel..
I couldn't help myself..
I never noticed if the slide scratched the barrel though.
You might have a sharp burr inside the slides opening.
And as Michael said it is a tool that's meant for combat use and a scratch or two on the barrel isn't gonna hurt anything..
Shoot it & Enjoy!!
While I'm sure mine isn't highly polished, I never noticed a distinct scratch either. I think B92 may have hit it on the head. Look for a burr on the end of the spring.
As an aside, when I first got my PPK/s, I put the spring on backwards when reassembling it. Not for long. I noticed that something wasn't right, but I don't think it mentions in the manual that there is a "right" way and a "wrong" way.
MLBs right there's a tight end & a loose end
The tight end goes on the barrel first..
My aftermarket Wolff recoil spring on my HK P7M8 was the same way..Funny the factory spring was the same size at both ends?