The only problem with those ball and socket hinge joints is that by the time they need adjusting, the ball end screw may be difficult or impossible to turn. I have soaked some for several months in good penetrating oil, applied as much heat as I dared without discoloring the action like an "old Ed Lander" case color job, tapped with a brass rod, etc., before I could budge it. I have seen many that are buggered up by heavy handed attempts to move. The two hole spanner type are even more of a problem if frozen because the two tits on your home-made spanner will not withstand the same torque as a screwdriver in a slot. I have an I grade action that has been soaking in penetrating oil for well over a year, and I fear it may be beyond hope and will have to be drilled out. I have a replacement from another I grade that I bought from Bill Schodlatz. Maybe he'll be along to tell us how much fun he had removing it. Hopefully the thread size or pitch did not change.
Miller told us that the ones he measured had straight threads, and I absolutely believe him. He's a machinist who knows his measuring tools. But we know Lefever was constantly tinkering and experimenting with his designs. The only two I've measured both had a slight taper to the threads. I have the dimensions for one from a D.M. Lefever crossbolt in my notes: .519"-.520"OD at the screw slot end and .515"-.516" at the ball end. Thread diameter at root of threads at the top is .481" and .479" at the bottom. Thread pitch was, near as I could measure, approx. 8 threads in .312", which would equate to around 25.6 threads per inch. Nothing on my standard or metric thread pitch gauges matched. I did not measure the internal threads in the action knuckle, but there is not much adjustment there before it gets too tight to turn. Fortunately, my D.M. crossbolt only needed a wee bit. Keith Kearcher has said that he has polished the threads to pick up a fraction of a turn more on really loose guns. I seriously doubt that this system permitted the use of poor or inexperienced craftsmen. Quite the opposite, and probably a big reason no other maker adopted it.
I own and shoot Lefevers and L.C. Smiths. Both are nice and both have their faults. The safety aspect of not having intercepting sears has been discussed before. Both have weak buttstocks (fragile around the inletting)and are prone to damage around the action and sideplates. Both are difficult (read expensive) to properly re-stock. The cost to do it professionally will often exceed the value of the gun. Glass bedding a Model 700 varmint rifle is one thing. Glass bedding a classic double makes me squeamish for some reason.
