Free: Contests & Raffles.
By definition 594 is pretty useless without universal gun registration. There is no way to know if a gun has been transferred or not since there's no record of who owns it. Handguns get registered when purchased from a state license holder but that info doesn't go with the gun. I have about a dozen on the record under my name. I only still own one of them. Unless somebody says they gave the gun to another person there would be absolutely no way to know. They have to register every gun to make it work.
Actually, you cannot let your granddaughter shoot your guns either, unless of course you are giving it to her as a "bona fide gift"