Colleagues,
Late post on this one, but I have had a GPR flint for many years,
a kit, in .50 cal, and it used to win matches for me at the
MMan get togethers, when I still had good eyes.
It now has a chambers vent liner, and the TC hammer swap.
I did have to polish and stone the lock and frizzen pivots
to get a hot spark.
I thought the kit was pretty easy to assemble and finish, but
I did take a lot of wood off with rasp and sandpaper.
I blew the bedding of the barrel breech and tang, so it ended
up with MicroBed under the tang and behind the breech.
It doesn't show, and it may have helped accuracy.
Just press on, and build the rifle.
Mainspring