I guess I should have stated that with this gauge, you zero out the dial using the supplied .700 diameter ring, then when placed in the barrel it read .051, so effectively .751 as a starting point.

Bob, it took me a moment or two to understand your table of figures, but now I see what you were saying.you have a difference between the bore of .751, and the muzzle of .722, giving you .029" constriction. It depends on whose chart you read, but it's certainly closing in on full.
My only question is your table doesn't seem linear, and looks like it bells in the last inch or so.
All of my Parker choke reamers are very straight. (but tapered, duh)

That's what I'm concerned with, that much constriction in the last inch or so. Doesn't seem right to me?

That chart is on the money. That said, I think every gun should be pattern tested with whatever load you will be using.

I wish I could understand all that machinist mumbo jumbo but I don't. I always considered .030 as the start of the full choke range but the patterning board results are what really count.

Edgar, with a straight line (tapered) cutter how did they arrive at the 'ogee' at the beginning and at the end of the length of the choke taper? Was the ogee the result of the final hone and polish?

I recall reading that Parkers produced in Illion did not have the ogee that the Parker Bros. craftsmen finished the chokes with... I wonder why not and if the transition from the cylinder tube directly to the choke cone would affect the pattern by the possibility of more shot pellets being deformed?

I have a 12 bore with .041" and .042" of constriction that is certainly tighter than the .029" constriction suggested as full choke... so, what degree of choke should I call it?





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that is where my Elsie Longrange is - I think Super Foxes are typically around that or even just a bit more

i just call it extra full

Incidentally, this is the gun that Larry Frey used to win the New Year's Day Shoot with. It reaches out there.





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A straight tapered reamer is not going to yield anything but a straight taper. Any machining operation that yielded a curved surface at either end of the taper was either done by a hand lapping operation, or another tool. Of all the reamers in Hayes' tool box, there are no such reamers.

I Can't comment on this, because I have never read what you're refering to, nor do I own, or care to own , any Ilion Remington made Parkers

Cheerio tight. Not a British choke term, but a Yankee one, describing a gun so tight, you can shoot through a Cheerio and not break it.

My Fox Sterlingworth is .044" in both barrels. I believe it will shoot 1" groups at 100 yards