Krakow
with any gun that has been re-barreled you should check that it is firing in the centre of the primers. Take two empty primed cases and fire them in the gun. Check that the pins are striking in the centre of the primers. When a new gun is made the striker holes are drilled after the barrels are fitted. When a gun is re-barreled it is some times difficult to get the new barrels in the centre of the pin holes.
I hope this helps.

John Foster