This is a question that has had me puzzled for many years and I've never had a reasonable explanation for their presence on Single Shot Rifles. During the late 1800's and into the 1900's these could be found on both US and British made rifles. I cannot see them being there for the purpose of strengthening the chamber area. Some rifles have three, others four of these small raised areas surrounding the barrel immediately in front of the receiver ring of the action.
Could it be to cut down on vibration arising from the firing for the rifle?
I'd be obliged for your thoughts or suggestions.
Harry
