Parker Gun Collectors Association Forums - Parker gauge determination

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Quote:

Originally Posted by Robin Lewis (Post 259342)

My guess is that you need to measure the bore diameter (not chamber or choke area) to know for sure. According to http://www.hallowellco.com/bore_size_chart.htm you will measure .729 if its a 12 ga and .693 if its a 14 ga.

I found an interesting discussion on the A/B topic at https://forum.cartridgecollectors.org/t/16b-guage/9315 which my clear up or maybe confuse the issue.....?

Interesting topic none the less. That thread concludes with the following text:

All depends what you call the gauge.

If you are referring to it at the theoretical diameter of the bore (I am talking here about the British standard because US guns were following it in these old time)
we have for example
12 gauge = 18.52 (=0.729 inches)
14 gauge = 17.60 (0.693 inches)
16 gauge = 16.81 (0.662 inches)
20 gauge = 15.62 (0.615 inches)
From the chart I posted you can see the 12B and the 16B have these theoretical values.

About the A ctges, because there is a conical recess they also have the same bore diameter.
Therefore the assertion : 16 B and 20 A guns have a different bore diameter is false.

If you are referring to the standards the Brits used :
12 gauge can vary from 18.80 (0.740) to 18.03 (0.710) (this last one being in fact theoretical 13 Ga)
14 gauge can vary from 17.81 (0.701) to 17.20 (0.677) (this last one being in fact theoretical 15 Gauge)
16 gauge can vary from 16.99 (0.669) to 16.18 (0.637) (this last one being in fact 18 Gauge)
20 gauge can vary from 15.90 (0.626) to 15.14 (0.596) (this last one being in fact theoretical 22 gauge)
To which value is he referring in this case ??

If always at the same period you are referring to the US way of manufacturing I have no info about the spread.
Perhaps (and I think) the spread was narrower.
To which value is he referring ??

If he is referring to the nowadays US standard, we get :
12 gauge can vary from 18.92 (0.745) to 18.41 (0.725)
16 gauge can vary from 17.40 (0.685) to 16.89 (0.665)
20 gauge can vary from 16.13 (0.635) to 15.62 (0.615)

Conclusion :
Saying that this corresponds or not to a 20 gauge is pretty inaccurate.
You have always to tell the period of time, the standard and the exact value of what you call a 20 gauge bore.

Shortly, I would say that, taking into consideration the historical context:
a 12 B and a 14 A guns have the same bore diameter
a 14 B and a 16 a guns have the same bore diameter
a 16 B and 20 A guns have the same bore diameter

Thanks, Robin, but this ol' country boy is REALLY confused now!

Quote:

Originally Posted by Brian Dudley (Post 259345)

A lot of early guns are oversized in the bores. So bore measurements alone will not give a true answer. If records are available, a letter is a good way to confirm original configuration.

Thanks so much, Brian.

Hypothetical question--given the low serial number and old military surplus steel barrels, is the gun more likely to be a 14 ga. or a 12b or can that question not be answered? I think only about 150 14 gauges were made. I assume a 14 ga. would be more valuable than 12b?

Given the rarity of 14 bore Parkers, It’s more likely to be a 12B.

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Without seeing the gun but knowing it's S/N, I'd guess it's the lowest grade back action lifter gun with a straight grip. Some of the old back action guns were chambered for the 12b brass cartridge which has the same dimensions as a 14ga. paper shell. I'll also venture a guess that the bore diameter is equivalent to an 11ga. gun. I have actually seen 12b/14 entered in the first stock book. I have one S/N 63 and I know of at least one other that a member has.

Is Richard Hoover still with us? He was the expert on these early odd gauges

Richard Hoover, Charlie Price and Austin Hogan did a lot of research on the various bore and chamber sizes of the very early Parkers.

I have files containing all the known (at the time they were all with us and active) 11-gauge serial numbers and there are no three digit serial numbers in those files.

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Quote:

Originally Posted by Dean Romig (Post 259350)

Given the rarity of 14 bore Parkers, It’s more likely to be a 12B.

.

Thanks, Dean...........I was hoping for a 14, but I expect you're right on this one.

Quote:

Originally Posted by Chuck Bishop (Post 259364)

Thank you, Chuck. I'm still somewhat confused as to what I have. How could I tell for sure other than having someone measure the bore diameter? Someone did this for me about a year ago and came up with the 12b. Don't know if I should get a second opinion or not! Thanks! Jack.

P.S. I just found an all brass unfired REM-UMC Best 12 gauge shell that will not go into either chamber of the gun. Not sure what that means, if anything, though.

If that one is a 12A you need to try a 12 B and if a 12B won’t go in either chamber at all, then in all likelihood it’s a 14 gauge.

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