Culpepper, nailed it on the durability piece, they are fragile and it doesn’t take much for the accurange tombstone to break free or something else to go wrong, these appeal to a collector like myself, who spends time gathering all surplus take off M40 parts for a build and want the closest thing to a real deal M40 without spending $40k+ at a Rock Island auction. It’s the nostalgic and historical aspect that drives the passion behind doing a build like this but I can totally agree to the aspect that it is a lot of money for something that won’t get used a lot if any at all and in comparison to modern optics is usually classified as junk.