I am currently stationed in MS for the Air Force and will be moving back to MD. I already bought a Walther P99 and it's legal in MD. My question is, from what I understand I don't have to register my gun in MD but I can if I want. So if I don't register my gun how can I prove that I purchased it legally? With a recipt? Also, the gun law are freakin rediculous in MD anyone know any good organization I can support to help change these laws that violate the constitution?(IMO) Thanks.