My understanding is the LC mark applies to a 3" or longer chamber. 2 3/4" chambers would thus still be marked as C. I know that 3" chambers were available in that era, but don't recall what their proof charge was, whether it was heavier than the 1oz this gun was proofed with.
Mark I appreciate you posting the marks on this gun, this is how we all gain knowledge of the marks. When you get a chance it would be nice if you could measure the actual chamber length & post them. In all likelyhood they are 3" as Larry stated.
