I use a synthetic rod with a 12 ga tip I got from Log Cabin which Imounted on it.
I did drill & thread the face of the tip to accept standard 10-32 accessories so I could use a ball puller to remove wads if I get the loading sequence wrong. [:@]Or a worm if I loose a patch downbore.
Not 100% sure, but the synthetic rod seem to be made of delrin. Pretty flexible, but tough! (I've used delrin in making game calls, and the rod reacts the same when drilled - long curly ribbon-like strands when drilled or turned on the lathe.)