I've received a several new locks in the past with frizzen springs that weren't lined up close to the lock plate. (spring arm extension bent out away from the plate) I either replaced the spring, or sent the whole lock back to the maker to fix. They need to know this is a problem, afterall, and inspect all locks before sending them out.
After our last shoot I was cleaning my own lock (15 yrs old) and noticed the same problem had surfaced and it had been mis-aligned for some time without me noticing. The screw holding the spring was tight, but bottomed out in the blind threaded hole. The lock functioned perfectly as always, but severe wear to the frizzen cam occurred, as seen in picture.
Fortunately I had a spare spring so I swapped them and ground and polished the frizzen cam so it works fine again.
So check your lock, because this problem is easy to overlook, and always inspect new locks for this problem.
One of mine made about 20 years ago came in with an altered frizzen spring that wouldn't allow the frizzen to cycle
all the way over. I corrected it and examined the mechanism which other than a cleaning which it got,it was still as new.
This lock was my version of the small Manton or Bailes that I sent to Germany for target pistols beginning in 1979.
This one had my USA logo and was made after 1989.
I also finished a job for a man in Wisconsin who sent me the plate with frizzen installed but NO frizzen spring or
holes drilled and a Chambers late Ketland frizzen spring along with a double throated cock.I made up a fast
mechanism and it looks good and works really well.I had wondered and thought of this for a long time and it
seems to be a good combination of parts from 3 different makers.
Bob Roller