I have numerous old SxS's that don't check round with a inside mic. I suppose a top SC's shooter would find it unacceptable, but for casual shooting they seem just fine. If you had a tapered round plug you could try and repair it if you found it necessary. I had a Parker that fell and made the barrel really out of round - I did as for mentioned and you can't tell now. In the Double Gun Journal, Vol. 16, Issue 4, there's a nice article on Lindner doubles I think you'll really enjoy. Call 1-800-447-1658