Those wear marks are called Sig "smiles". You will find them on all Sig handguns. Sigs are some of the most accurate handguns made. The smiles come from tighter tolerances than most handguns, including Glocks. They are purely cosmetic and should not deter you from buying a used P250. As to the scratches inside the barrel, they are not normal. I have never seen anything like you describe. It's most likely something the "user" has done. If you can, put some rounds thru it and see how well it shoots before you buy it.

Scratches in the barrel are definitely not normal....if you buy, I hope it's really cheap.....

The scratches are not inside the barrell, sorry for my bad english. The scratches are outside like the Sig smiles hud mentioned, inside it its perfect.

Thanks, i didnt know about the Sig "smiles"! As for the scratches, sorry for my bad english, i meant inside the gun when i disassembled it, not inside the barrell. I looked the barrell inside and it looks ok. Beside those Sig "smiles", there is a little dent over the top of the external part of the barrell, where the slide makes contact when the gun shoots.
Btw, is the P250 a good gun, is it worth? I havenīt shot yet but it looks and feels really nice. Love the ergonomics. Any thoughts?

Outside of barrel are Sig Smileys as stated above and are harmless......The Sig P250 is an excellent pistol, I own three. You can easily change size and caliber with just a kit. Please keep in mind that the trigger is Double Action only, very long and very smooth, very similar to a revolver. I would suggest you ask your friend to allow you to fire some rounds through it and see how it feels and works for your needs....JJ