Quoted from Don Getz the premier barrel maker.
I used Hadaway locks on the first three guns I built, first one in 1970. Not sure when he started in business, but the ones I used were very good. From what I understand, Doc Hadaway did have a hand in designing the flint lock for those
early TC Hawken rifles. The cock and frizzen on the TC guns are the same as his lock, well, almost. The frizzens on his
locks were made of good steel and were appropriately hardened, whereas the frizzens on a TC lock were only "case hardened", which means they only have a hard shell on the outside. That is why a TC flint will eventually quit
sparking if you shoot it a lot, the hard shell will eventually wear thru then you are into soft steel, which will not spark.
Another unique thing on a Hadaway lock, he had a set screw in the tumbler which could be adjusted to vary the amount
of sear engagement....a rather nice addition, but probably not something one would find on an original lock..........Don
More;
Gentlemen, The original Doc Haddaway lock was produced from a mold which replicated a 1790 John Bonewitz rifle. It is a suburb example of workmanship and replication. If I remember correctly they were on the market after Hamm and before Siler. They can be found but are few and far between. The only other lock which does justice to the lock design used by Bonewitz and the Womelsdorf school is currently offered by Jack Brooks, Colorado.
A while back I ran into Haddaway's son. He had 4 locks that he didn't want to part with at the time. I tried and I tried and I tried again but to no avail. So if you find one consider it a treasure.