I must be 18 to purchase tobacco
I must be 21 to purchase alcohol
So what is the problem with firearm transaction laws being the same for every state?
Wouldn't that make it easier for legal interstate sales and easier to prosecute illegal sales?
The age to purchase tobacco is not federally mandated and is not 18 in all places. Neither is the drinking age, the drinking age was strong armed by the feds in the 80's by threat of withholding funds from states that do not set the age at 21.
The problem? See everything above in the thread.
Interstate transfers with limited exceptions already require an FFL and as such a background check. Furthermore, they(the feds) already fail to prosecute many firearms offenses, it would not make it any easier as they choose not to already.