Hi Ron!
Not necessarily (did you get "hosed")... I'm a bit suspect about the gauge itself when your screw chokes aren't matching?
As well - while chokes are a lengthy topic - the correct way to measure constriction on fixed choked guns (Parkers) is best done with a bore dial gauge like this:
http://www.intlmidway.com/intl/eprod...eitemid=225330
It will tell you constriction to the bore, choke length, etc. And frankly - I use one on all my Parkers (you can also get some idea if the tubes have been cut down, looking at the length of run on a choke)...
While not an average "home owners" item, most good shops and smiths will have one and be pleased to help you out. It only takes a minute or two...
Hope this help,
John
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