Well Ed and Heinz,
you are wrong on this one. It is not legal to own, but not attach a stock (Unless it is specifically exempted or registered as an SBR) Here is the proof. Remember way back when when many an artillery luger rig was butchered by either grinding off the stock lug or removing the attaching iron from the stock? Why did they do that? Because to comply with the Fed law you could not "constructively" possess both the artillery luger and stock. So to possess an artillery or navy rig legally they had to butcher the luger or the stock. (Unless of course it had been registered under the NFA) Then they gave artillery lugers and others an exemption as outlined by Heinz. Now if you want to pick at straws, think about this. Say you have a qualified original artillery luger and original artillery stock. You are OK because of the NFA exemption. Now you add a standard 4" luger, a BYF 42 for example, to your collection, which is not exempted under the NFA for a stock. As long as you don't mount the artillery stock on the BYF 42 you are probably OK, because you have the exempted artillery to go with the stock. But if you just have a BYF 42 and an artillery stock, (which of course will fit on the BYF 42) and no artillery luger yet, you could be found in constructive possession of an unregistered SBR even if you never attached the artillery stock to the BYF 42. Unless someone is focused on, due to some related or unrelated law enforcement investigation, or bring attention to themselves, ie online or offering for sale, these are probably mute points. My worry is that none of the new gun control laws and most of the past laws and decisions, allow for all the variables especially when dealing with older collectible firearms. The liberals and politicians are pushing hard now to restrict and remove our firearm rights as never before. The last thing they care about is if a valuable 100 plus year old collectible luger snail drum becomes contraband because it holds over 10 rounds of 9mm ammo. Or a 100 year old artillery luger becomes contraband because it has a stock. California for example, already did this to luger snail drums years ago when they enacted a high capacity magazine ban. First they grandfathered previous hi cap mags, but you could no longer buy, sell or transfer them. Then they flat out made them contraband unless you were law enforcement. (This is working through the Courts right now, but they still enacted it already). To sum up: yes there is a legal principal which applies called constructive possession, like Schutzen-Jager stated. The law is one thing and actual enforcement is another. Common sense and spirit of the law used to be the standard of law enforcement. ie, Jimmy sells drugs and knocks off liquor stores. Jimmy is found with a stolen BYF 42 Luger with an Artillery stock. Jimmy is getting charged with possession of an unregistered SBR. John Q citizen has a loud argument with his wife. His BYF 42 and an artillery stock are on the table when police check the welfare. No crimes, just loud words, Officer compliments John Q on his fine Luger and leaves. Well brothers, those days I am sad to say are probably gone. Trust me, the gun control laws coming down if enacted will affect your collectible shotguns, Colts, S & W's and Lugers. They are not just going to affect those evil AR 15's. Oh, they will grandfather the existing guns right? Wrong, that is only step one. Like in California, first they grandfathered existing hi cap mags, then a few years later banned them outright, grandfathered or not. They are pushing more gun laws and taking away enforcement discretion. Oh they know their anti gun laws violate the 2nd amendment. But they don't care, they know it takes years to repeal these laws at great expense and little likely hood their repeal will ever succeed. Consider this horse beaten, good day to all.
