I've only seen one actual Type G (Carolina Gun) ramrod pipe and it was on a Williams signed gun (pre-1745) that was found in the Suwannee River in 2005. The ramrod pipe material (brass) was very thin and wouldn't have served if it hadn't had ribs pressed or stamped into it for some rigidity. The tab on the pipe went all the way into the barrel channel and was splayed out. Pressure from the barrel kept it in place. There was no entry pipe and the ramrod, which was visible in the lock mortise, was tapered to a point. The ramrod pipe size was no more than 5/16" in diameter. The buttplate and the triggerguard were missing from this piece, but the sideplate, wrist escutcheon and flintlock were present along with the one ramrod pipe. I saw a Gillespie Mtn. rifle in Blairsville, GA a few years back that had the ramrod pipes installed the same way. I've wondered if they might have been influenced by the thousands of Carolina guns that were imported into the SE previously.
James Levy