Eight Gauge, but not a Parker

[Bill Murphy]

OK, here is the verdict on the Davenport bores and also my method of measuring eight gauge bores when we don't have a bore micrometer big enought to measure the eight, or even a ten. I first marked off the 16" and the 8" depth mark on my $90 Manson wall thickness gauge. I then measured the wall thickness of the Davenport barrel at those depths, from the muzzle. I then flipped the gun over to see if the wall thickness is the same on the other side. I then measured the outside diameter of the barrel with a vernier caliper. The same measurement could be taken with a 1" to 2" micrometer. The wall thicknesses at 16" and 8" are .160" and .145". The outside diameter at the 16" and the 8" marks are 1.180" and 1.140". The bore diameters, calculated by doubling the wall thickness and subtracting it from the outside diameter, are .860 and .850. Allowing for errors in measurement at any of the many points measured, done on a bench with no vise for the gun, I would place the bore diameter at an estimated .855. A more careful measurement of the muzzle at .800, rather than the previously posted .790, would place the choke measurement at .055, a nice full choke for an eight gauge. Test fire to come when the snow melts off the pattern board area.

[OH Osthaus]

Originally Posted by Bill Murphy

Test fire to come when the snow melts off the pattern board area.

i would think the first shot from an 8 gauge would take care of the snow on the pattern board

as for your math- agreed- as long as you have two of the variables - you had wall thickness and outside radius, you can get the third.

Before I acquired my gauges I bought a gun I wanted the wall thickness of. I borrowed a bore gauge, measured the outside and did the math. Later when I assembled my set of gauges I repeated the exercise and then measured the walls- the numbers agreed. just don't tell the late Mrs Peterson I actually used the math she taught me in school - the shock would kill her again.

[J.B. Books]

It sounds like an interesting gun....... but