Old thread, I must've missed this somewhere along the way....still yet, I gotta agree with Cylon, "a friction locking worm is intriguing...."
I guess the only "worm" I have ever used was the screw type ball worm, and the two legged twisted wire worm for removing patches. Both required screwing into the ramrod.
I also have in a small collection of "worms", and one what must be a "home-made" worm with steel welded barbs, likely for a ..69cal, or there about, never used it because it all looks to be welded to a full 3/8" thread about 1/2" long...a really stout looking worm that one could likely use as a Frog Gig in an emergency.
I have held on to that ugly beast hoping someone would come along and tell me what it really is.
Uncle Russ...