 The advantages touted for "overbore" are a perceived reduction in recoil, and a lessened shot deformation for improving shot patterns.Generally the constriction ranges for chokes will be 0.00-1.15 mm (0.00-0.045 inch) while the constriction for relatively common turkey chokes may be as much as 2.50 mm (0.10 inch).Choke is measured experimentally by observing the percentage of pellets in a charge that impact inside a 75 cm circle at 35 m (25 m for "cylinder" and "Skeet1").