Nut Boring

[edgarspencer]

Originally Posted by Dean Romig

Contractors in the barrel department at Parker Bros would hold the barrels up to a light source, like a window with an opaque covering, and ‘regulate’ the tubes together this way. I believe they would simply thump them with their fist as a hammer.

I assume you mean when they were wired, but not yet soldered.

[Dean Romig]

I don’t think anybody can answer that question beyond speculation.





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[edgarspencer]

Maybe not, but surely you could take an educated guess. I sure hope my soldered and finished barrels can take a fist thumpin without changes the POI.

[Dean Romig]

I don’t know.. I read a story where a side-by-side shotgun had always shot way to low and the young owner complained of this to an old-time gunsmith. The old timer took the gun, sat on a stump and laid it across his spread apart knees and thumped it a couple of times then said “Try it now.” And the pattern had come up but not quite enough. A repeat performance by the old-timer brought the pattern right where it should be… Keeping in mind that this is a story from within the pages of a sporting book.

Maybe yes - Maybe no…





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[Cold Spring]

Originally Posted by Dean Romig

Contractors in the barrel department at Parker Bros would hold the barrels up to a light source, like a window with an opaque covering, and ‘regulate’ the tubes together this way. I believe they would simply thump them with their fist as a hammer.

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Parker Brothers may have done some of what I describe here differently, but typical American maker practice was to straighten each barrel tube after it was drilled and first-pass reamed. A heavy wire or rod was placed horizontally across a frosted glass mounted in front of a window or source of light. Any crookedness in the shadow line indicated to the so-called "setter" just where to spring the tube to straighten it. Earlier on this was done judiciously with a hammer and later the practice evolved to using a mechanical press.

The next operation was to put the individual tube in a lathe and turn its exterior to approximate finished size and contour. Often it was necessary to re-straighten the bore as described because the removal of metal may have released internal stresses.

Double shotgun regulation was done after the tubes were tinned (exterior dip coating of molten solder). Both tubes were "mated" and held together by pieces of metal soldered between them and at fixed intervals to hold the tubes the correct distance apart. Great care was taken to see that the tubes were in the same plane and were properly adjusted to regulate and thus prevent cross-firing. Lastly the top rib, bottom ribs and loop lug were put in place, held together by wire wrapping and wedges. Then the assembly was heated in a furnace with powdered rosin or a soldering flux applied along with some additional solder.

Afterwards the bores and chokes were finish reamed and polished using increasingly larger diameter bore reamers, a choking (tapered) reamer and finally a pack reamer and polishing rod.

[Stan Hillis]

The regulation of double barreled guns has fascinated me for many years, mostly that of shotguns, as opposed to double rifles. I became aware that not all double barreled shotguns are properly regulated with just any old load early on. Some cannot be found to print the individual patterns atop each other with ANY load but often, when a side by side shotgun crossfires, all that is needed for perfect regulation of the patterns is to try different weight payloads and velocities.

This is just personal observation, but most often when one cross-fires badly it is because the payload is too light and/or the velocity too high. The last example I ran into is my dedicated quail and woodcock gun, a Philadelphia Fox 20 SWE. I wanted to use 7/8 oz. loads in it so when I first patterned it that's what I tried. They were running at about 1200 fps, as i recall. To my chagrin it cross-fired to the tune of 8" at about 20 yards, equally so with both barrels. I was sick when I saw that. Turns out that all it wanted was 1 oz. loads at about 1150 fps to put those sweet patterns right on top of each other at POA.

[Dean Romig]

Thanks Frank for taking the time to go into the detail of the process that I didn’t take the time to explain, especially about the stationary wire to look through the tubes at. This is all explained in TPS as well. Again, thank you.





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[edgarspencer]

Frank, What is a 'pack reamer'? Same as PAC reamer ?

[Cold Spring]

Edgar, the so-called "pack" reamer was used for slow scraping or burnishing of the bores and chokes. It cut away very little metal and left them with a smooth surface and ready for the polishing rod. See attached pic which may be greatly expanded.

For info, this and my preceding reply are excerpts from my second to last DGJ article which was in the Summer 2022 issue when its plug was pulled. I requested both to be returned, and some day I may find another publisher for both.
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[edgarspencer]

Originally Posted by Frank Srebro

Edgar, the so-called "pack" reamer was used for slow scraping or burnishing of the bores and chokes. It cut away very little metal and left them with a smooth surface and ready for the polishing rod. See attached pic which may be greatly expanded.

For info, this and my preceding reply are excerpts from my second to last DGJ article which was to be in the Summer 2022 issue when the plug was pulled. I requested both to be returned, and some day I may find another publisher for both.
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I sincerely hope you are able to publish it, as I find this fills in some blanks for me. I have found other references to a fine cutting/ burnishing tool, but not as it pertains to Parker Brothers.
I am especially interested in the tools which were 'expanded' by use of wedges, or shims. Peter Johnson references such tools in his book. The British also used tools, employing hardwood for increasing the cutting diameter.
Lastly, I was under the possibly false assumption the the ribs were not part of the initial soldering process, but installed in a second operation, because of the use of different, or softer solders.