At 1.1" you must be referring to the bottom of the threads right? I don't think he was referring to proof loads. Think about the diameter of a 338 Lapua at the case head vs the diameter of the small shank barrel. If you chamber a WSM or RUM in a small shank you only have chamber walls 1/4" thick and that's to the top of the threads. The small shank is 1.055" and the diameter above the extraction groof of a WSM/RUM case is .555. 1.055-.555=.5. .5/2=.25". The Lapua case is even larger. The chamber walls are mighty thin, too thin for my liking. I'll try to find the thread for you. You may be right about the recoil lug but I don't know of anyone who's done that. The recoil lugs slip over the barrel shank easily and in that case I doubt they provide much additional strength.