Quote:
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.