FWIW here's the DIY method that the late Zonie used, where one should be able to use it for round stock:
"If you have a piece of 1/8" or 1/4" thick steel plate and a few drill bits you can do the final ramrod sizing using the best method available. This method of sizing does not cut thru the grain of the wood, which weakens it. Rather, the grain of the wood controls where the wood is removed.
To make the tool, drill a 1/2", a 7/16" and a 3/8" hole thru the steel plate. If you like drilling holes, used appropriate sizes or if you are limited, but have a rat tail file, you can drill an extra 3/8" hole and a extra 7/16" hole, then use the rat tail file to enlarge these two extra holes so they are about 1/32" larger.
When the wood blank is about 1/2 X 1/2 square, taper one end and stick it thru the 1/2" hole. Then pull it thru using some pliers. Move the ramrod blank to the next smaller hole and repeat the pulling thru operation.
Continue to do this until the rod is sized where you want it."
