Can chokes be opened by shooting over many years?

[J.B. Books]

Originally Posted by Dean Romig

A dial indicator or digital bore micrometer is the only way to go. It may read 'cylinder' at the muzzle with a graduated drop-in gauge but the bore could widen several thousandths behind the muzzles for a few inches.

Counting pellet holes and doing the math to get percentages is tedious.

The only times I shoot at paper is to find POI and to determine what shot size gives the best patterns with a particular gun.

Sometimes you can learn some interesting things beyond that. For instance I have a straight grip VH 12ga 28" with .013 constriction in the right barrel, it patterned 48% at 40 yards with 1 ounce of lead 6. I have a Remington 1900 12ga with 30" bbls and .014 constriction in the right barrel and it patterned 72%. One point of choke difference between them and one gun shoots Skeet/IC and the other Full. That is something very good to know whether you are hunting or shooting clays.