The 18.3mm is nothing to do with choking
That is the bore diameter. A mandatory stamping of the bore diameter of anything that comes out of Europe and the UK.
It comes from the old days when a gun could shoot thousands and thousands of shots a year and when they got serviced a bore measurement could be taken to determine if it was still safe. Yes, they shot them so much on wealthy sporting estates the bores would increase and thin the barrel wall.
So 18.3mm or .720" is the datum measurement.
That is the bore diameter. A mandatory stamping of the bore diameter of anything that comes out of Europe and the UK.
It comes from the old days when a gun could shoot thousands and thousands of shots a year and when they got serviced a bore measurement could be taken to determine if it was still safe. Yes, they shot them so much on wealthy sporting estates the bores would increase and thin the barrel wall.
So 18.3mm or .720" is the datum measurement.
