I AM NOT a Perazzi guy but a friend pointed this out, and I thought it interesting. You guys may have known this for years. I'm playing catch up. Kolar prints the number on their chokes for dummies like me.
Perazzi chokes are numbered from1 to 10 from the factory. Multiply the number by .04 and you have the constriction.
A number 1 x .04 =.04 (about a skeet choke). A number 6 x .04 = .024 (about an im mod) and a 10 is a tight son of a gun!! .040
Cool! Even I can remember that.
Jim