"Clean-out" screws, new or old?
I just looked at 26 drums on original American percussion barrels. All are old, from the percussion era. Eleven had old "clean-out" screws, fifteen did not. Another 16 old American barrels built with side bolsters or snails showed ten with "clean-out" screws and six without. These barrels are mostly double rifles, which might change the playing field, but my assembly certainly shows many original “clean-out” screws. Most have generous heads and slots, begging to be “screwed with”.
Taylor may be correct that they were made for drilling out the ignition path to the powder chamber and were not meant to be removed. Several of the double rifles have one head present and the other clearly broken off, which supports that argument. Although the sample is small, the higher percentage of screws in the bolster/snail group also supports the argument of those holes being the easiest way to complete the flash hole on those designs (flash holes in drums are easily drilled blind).
At any rate, as seen from my small sample, I think those drum “clean-out” screws were not uncommon in old original percussion era guns. Whether or not they were meant to be removed for “cleaning-out” remains up for grabs, in my opinion. Numerous broken off heads attest to the difficulty of removing them in practice, whether from the gunmaker’s intent of permanency, or the shooter’s neglect of not removing them ofter enough to keep them from rusting in. If my intent as a builder were that they stay in place, I would have filed the screw slots away so no clumsy owner would be tempted to break the head off with a forceful screwdriver.
Who knows? Bill Paton