Going off memory,
This small hole is smaller than the touchhole, and is a patent idea I believe originally of John or Joseph Manton.
The idea being to prevent any powder from sitting directly over the touchhole. I wish I had my Manton books as I can see the patent pictures clearly i my minds eye, and the photos of the lock with the lip!
Something about allowing free air travel whilst loading, from the days when a pan was primed first, is lurking in my memory too....
was it that the small hole concentrated the air as the load was rammed, heating it so that no moisture remained in the breech ?
This is agony!
Wish I had not loaned my books years ago and not got them back!
Mike, I don't think self priming.
I know Col. Hawker said if you owed someone a grudge, encourage them to get a self priming lock!..They always go off slow, he said!
Smart Dog will know.