On a properly fitted pin and hook there is no movement on firing so there is no need for cushioning. The same goes for supposed stress of cocking, operating ejectors/extractors and what stress is involved with opening and closing the action? The hook and pin are a simple hinge with little bearing weight. I maintain that there are many many double guns that are quite functional, tight and on face after many years without ever having the pin and hook lubricated with anything more sophisticated than an occasional wipe down with sewing machine oil. Keep the pin and hook clean and free of corrosion, which only requires a slight amount of corrosion resistant lubricant, shoot ammunition that is appropriate for the gun and the gun will out last you. I have a 125 year old LC Smith that is tight as it was when it left the finishers bench in Syracuse in 1887 and a whole bunch of guns that are about half its age and absolutely non are loose at the hinge. Now over that time period I would suspect all never saw the likes of RIG, certainly not turbine engine oil and until recently anything more high tech than Breakfree applied to the hook and pin during routine cleaning. This has been a fun exercise but in the whole quite useless.
