Get your bore gauge into the muzzle. Measure the bore four inches back.

As you pull the gauge out, you will probably find you can't as the chokes will be tighter than the bore. In order to get the gauge out you will need to adjust it downwards.

The adjustments will show in thousandths of an inch. When you manage to remove the gauge, look at how many thou you had to reduce the gauge by to do so. That will give you your choke reading.

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