HELP with Euro choke stampings

[dilly]

Can anyone here please shed some light on what the North American equivalent would be to a Spanish SxS stamped 14.8/15.8 on the underside of one barrel and 15.7/15.8 on the other. I believe these to be choke markings but I have no idea how to translate them. Thanks

 

[Mark Dube]

choke conversion

If we convert those metric numbers to imperial, we arrive at a nominal bore diameter of 0.622 inches, which tells us this is a 20 gauge.

The barrel with the muzzle diameter of 14.8 converts to approximately 0.583 inches, subtract that from the bore diameter, we arrive at a choke constriction of .039 inches, which equates to Xtra-full. The second barrel (should be the right barrel) has a constriction of 0.004 inches, equating to Improved Cylinder.

One thing to consider is that these could have been changed since manufacture, the only way to know is to measure them with the proper tools.

Mark

 

[dilly]

Thanks very much Mark.

 

[MauserMike]

Are there any stars on the barrels? These are also commonly used by the Spaniards to indicate choke.