Hey Instructables, I have a question about the legality of a project that I'm designing, as I don't want to make something illegal. As those who follow me on this site know, I play a lot of airsoft. I've recently been trying to design a new kind of airsoft rifle, and I would like a bullpup design (the magazine well is located behind the trigger to make a shorter gun). I was looking around on the net and I found this http://www.mountsplus.com/AR-15_Accessories/AR-15_Scope_Rings/MZ-1022.html It's a bullpup conversion for your standard Ruger 10/.22 rifle. i checked the legality of this conversion for the state I live in, California, and found that it IS in fact legal, as long as you only use a 10.22 in it, don't use an automatic, your magazine contains 10 rounds or less, and the barrel over 18 inches, with an overall gun length of 25 inches. Normally bullpup guns are illegal in California, but since the 10/.22 is a rimfire instead of a centerfire, and the ban only applies to centerfire guns, this conversion falls into a neat loophole, and is legal for sale on a normal license. HOWEVER: I don't plan on putting a 10/.22 in this thing, I plan on tearing out all the internals of the conversion rendering it permanently effectively useless for a real-steel gun, and building a field-spec airsoft gun system inside it, making it basically a nonlethal toy for sports like any other airsoft gun. The final design would be built to the legal specs of a airsoft gun in the united states, with an orange barrel tip and a non-ballistic caliber. I can even make the final gun fit into the real steel size requirements if that would help the legality. Basically, I don't know if this is legal or not, and haven't been able to find it online. As far as I can figure, it would be legal because the conversion kit counts as a STOCK, rather than a receiver or firearm in and of itself, so that gives a lot more leeway I would think. I just want to be doubly sure before I begin this project, due to the heightened paranoia over guns and gun laws at this point, I don't want to be thrown in jail for making a toy.