"That rotary bolt,,it's not uncommon to see the small hole in the side where the stem of the yoke comes through a small amt.
Some are just machined that way. The hole is drilled very close to the outside edge.
It doesn't take much fitting/filing to reveal the cavity if you are not careful.
Some people get a little carried away and take too much off too quickly especially with a belt grinder."

Kutter I have taken many L.C. Smith's apart and everyone has that small hole in the rotary bolt. The coupler pin goes into this hole and protrudes ever so slightly. If the coupler pin does not go into this hole you cannot get the coupler to be in alignment with the top lever and will prevent the top lever to move and won't close.
I phrased that wrong in my statement above, I stated gun won't open. I figuratively jumped "the gun" in posting that.

Also I have never seen a worn out rotary bolt and I have some that are over a 125 years old. The part that wears is the slope on the extension rib causing the rotary bolt to cam farther onto that slope and then the top lever closes farther to the left of center. The best way to prevent that is to hold the top lever over when closing the gun, this prevents unnecessary wear on the extension rib slope.
There was a saying in that "an L.C. Smith never shoots loose".
That is also why there is a gap between the barrel flat and the receiver to let this wear allow the barrel to fully close.
Now they will get a gap between the breech face and that is caused by wear on the hinge pin.

Last edited by David Williamson; 12/20/20 10:44 AM.

David