Choke Constriction (Inch)
Percentage of lead shot in 30-inch circle at 40 yards Identification (Notches) Identification (Stars)
(Spanish shotguns)
Cylinder 0.000 40 at 40 yd

70 at 25 yd

IIIII notches ***** stars
Skeet 1 0.005 45 at 40 yd

75 at 25 yd

   
Improved  Cylinder 0.010 50 IIII notches **** stars
Skeet 2 (light Mod.) 0.015 55    
Modified 0.020 60 III notches *** stars
Improved Modified 0.025 65 II notches ** stars
Full 0.030 70 I notch * star
Extra Full 0.040 73 I notch  
Turkey 0.045 plus 75 plus I notch