Following up on Drew Hause's above post regarding The Hunter's Encyclopedia from the German proof house, is there data of actual measurements, current or old, of Parker barrels minimal wall thickness at end of chamber, regardless of length, for 12, 16, 20 & 28 gauge guns?
I currently own three Parkers on which I've made this measurement using Hosford and Co. barrel wall thickness gauge. The chamber minimum wall thickness data for these is as follows:
1.) BH 12b. on a no. 1 frame, R ≥ 0.088, L ≥ 0.094 (Damascus barrels)
2.) GH 20b. on an 0 fame, R ≥ 0.100, L ≥ 0.092 (Damascus barrels)
3.) DHE 28b. on an 0 frame, R ≥ 0.084, L ≥ 0.076 (Titanic steel barrels).
All of these have been shot for many many years (not by me) and measure up well in terms of min wall thickness and bore diameters. Kirk Merrington tells me that, in his experience, Parkers and other American guns tend to have wall thickness at end of chamber that are considerably less than found on English or German guns (in the 0.080"-ish range). Yet this does not seem to be problematic. The Sherman Bell articles of a few years, in the Double Gun J., regarding the strength of Damascus barrels would seem to support this conclusion.
Is there data somewhere that would show how low you can safely go with these thicknesses (or how low Parker went when they were making these guns)? I am currently looking at a 16b. Parker on an 0 frame where that minimum thickness (for a 2.5" chamber) is 0.068" on one chamber and 0.071" on the other, with all other measurement being fine; bores at 0.667, min barrel wall thickness at 0.030." This gun has very obviously been shot quite a lot. Is it safe?
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