After all of my years of small game hunting, I'm still trying to figure out why everyone wants a tighter choke? the double I started out with was chocked full and full. as a youngster of 10 years old I couldn't hit squat. Squirrels no matter how high were dead meat. My dad had a double bored for skeet. Rabbits and pheasants started to fall. the problem was that gun weighed over 8 lbs. and for a skinny kid of 10 with one arm hampered by Erb's palsy it was just too much for me to handle. I hunted in Jersey in the 50's & 60's, the so called golden years. I would venture to guess that 90% of the game we shot were within 10 yds. . well within the limits of a cylinder choke. As far jug chocking I remember Brownell's use to sell an inside the barrel caliper for the purpose. You stuck it in your barrel and measured the arms that stuck outside the barrel with a micrometer. The hard part was after getting the diameter opened up was tapering both ends of the choke part so you didn't cause an obstruction. Without that inside barrel caliper it would be difficult to do successfully. Now just realize that this is from an 80 year old memory. YMMV