Living in FL, I've bought several firearms FTF transaction before, but recently a question came to mind regarding buying a lower FTF for an AR Pistol.

The question is, does the original 4473 have to have been pistol/other for the lower the legally be used as a pistol?  I know if it was being transferred through FFL, it would have to be.

Also, anyone know if there is a way to reclassify it as rifle if I wanted to get the SBR tax stamp later on, or would I just buy a stripped lower classified as "rifle" and transfer everything to it?

All stripped lowers are now transferred to the customer as an "other" by the FFL per BATFE.  Pistols, firearms, rifles, and others can become an SBR on payment of the $200 tax.  Shotguns probably can too after you convince the BATFE you've turned your shotgun into a rifle.

The only problem w/ buying an AR lower FTF for a pistol build is you've got no real guarantee the original owner didn't make it into a rifle first, and now it can never be a pistol.  Safer to buy a virgin lower that you can get the certificate of virginity from the manufacturer, but YMMV.  One of those rare times when a paper trail may actually benefit you.

A lower is never classified as a rifle - it is "other".

Lowers built into rifles may not be built into pistols later, but lowers built first into pistols can be made into rifles and go back.  

No, there is no way to determine what it first was unless manufacturer records or photos or affidavits turn up at some later time.  Only way for you to know is usually if you were the buyer at retail.

As far as later building an SBR, you're free to apply for a tax stamp at any time and turn a lower, be it an other, pistol, or rifle, into an SBR.  But once it's been made into a rifle (as an SBR) it can't go back and forth anymore even if it started life as a pistol... though it can go back to being a non-SBR rifle later by taking off the short upper.

Thanks for the advice.  Guess I'll go with a new one through the FFL to be sure of the 4473 being "other"

Thanks for the advice.  Guess I'll go with a new one through the FFL to be sure of the 4473 being "other"

A used lower transferred through an FFL would still be marked as "other firearm". But if it had started life as a rifle, it would still be illegal to make it into a pistol, meaning, what's on a 4473 does not confer some magical legal status.

The only way for sure to know you are building a legal pistol is to get a virgin lower from a manufacturer in a first time transfer.

- OS

Or make it yourself from an 80%.

Well yeah that, except maybe the EP Armory ones!

- OS

It should be obvious whether or not the lower has ever been assembled...ie...scratches or marks.  I have purchased a couple of stripped lowers from individuals and in both cases, there were nary a mark on either one....leading me to feel confident that they had never been attached to anything,  If it was scratched or showed any signs of having been previously assembled then I would not take a chance on using for a pistol build.