In most states face to face transfers are fine as long as both parties are legal residents of said state and aren't a prohibited person for any reason. IE, if it's illegal for you to buy a gun in the store, you can't buy it from private parties either(you're felon or something etc etc). Here in NJ you need a handgun permit but you're fine as long as you have it.
If you need a handgun permit in Maryland (beats me) to buy a handgun, you'd both still need them.
Being a man I had to buy a Colt. But being a super awesome manly man it couldn't be any Colt, it had to be a 10mm Colt Delta Elite. I now feel ready for the zombie invasion
9mm, .40, .45, Indian chief, doesn't really matter, cause 10mm kicks all of their butts! "