I have found on about every VOPO luger I worked on, that the chamber was from a bit tarnished to in a few cases needing finished reamed, I would at the least polish the chamber with nothing more then cocoas cloth, you can even wrap it around a hard wood dowel and use it like a mandrel, however polish very lite only, you don't want to change calibers....and watch that Tinker fellow, he has even been known to sell Lugers to wifes of unsuspecting husbands.....