Dr. Drew:

As I understand it now, the right tube is as it was going through London Proof in 2017 and is stamped 18.5 mm on the flats (which translates to .728). The left tube, while also marked 18.5 mm, is in actuality now measuring .735. This gun was listed and sold as having 23k on the right tube and 20k on the left. At about 20-inches from the breech on the left tube, both Mark and I found a couple of thin spots of ~18k (on the left wall and near the top rib, [somebody has been chasing a pit]).

Now, two different tools were used to measure these tubes, Kirby's is lateral, the one at MW Reynolds is vertical and a copy of the one used at Holts (made & marketed by Tony Galazan here in the USofA) so there is clearly room for interpretation. Kirby has kindly offered to let me return the gun but is willing to allow me to proof-test it (in my own-way) here first. From looking at your pressure curve above (thankyou so-much for that!), I'm even more comfortable with it now.

Instead of measuring (& recording) the whole length of a barrel, I was trained to measure gun barrels by looking for the "thinnest-point" (which is what is recorded for most guns being sold these days). In almost every case, a gun being measured will usually be significantly thicker throughout the rest of the length of the tubes. If there is going to be a thinner spot, it seems to usually be in the 12 to 24 inch range on a set of 28 to 30-inch barrels, as it was here. I don't remember exactly, but these barrels were somewhere in the 40k range near to the breech and then thinning down in the 18-24 inch section. Since those "thin" spots very localized, at 9-inches from the breech I'd suspect that the tubes were still well-into the 25 to 30-thousandths range. The muzzles were also in the 20-25k range with the left tube being closer to 21k (& is probably the reason why it has so-little choke left).

Your pressure curve has also helped me decide the shells that I'm going to use for my little experiment. I really don't see much need to abuse an older gun any more than necessary, so 1 1/8 ounce target loads are going to be the ticket for me now, and I really don't expect any problems. A couple out of each tube should be sufficient.

The real challenge I'm facing these days is navigating on crutches in snow and ice(!).

Last edited by Lloyd3; 12/31/23 05:06 PM.