Originally Posted by Researcher
I sure don't see that the muzzles of my WS-1 bored Model 21s are particularly thinner than any other open bored guns. Certainly not thinner than skeet bored Browning Superposed Lightnings.

You need to have a bore gauge to understand the WS1 choking. Externally, the barrels are the same for both WS1 and WS2.
The WS1 choking does make the barrel walls thinner for a short distance---its a matter of personal opinion whether this is significant or not.