So i recently bought a used colt stripped lower off of gunbroker, and apparently it came off of rifle. It was checked into my FFL as a receiver and transferred to me as such, however, so am I still permitted to build a pistol from this? Or since it started its life manufactured as a rifle is it a no-go? I would think it wouldn't matter since obviously we can't be expected to know it's entire history other than what it was for sale as at the point of sale, but I'm curious if the ATF has made a statement on this in the past.

If it can be proved it was built as a rifle, then building it into a pistol would be a no no, with the serial number on it, it has been reported to the BATF by the manufacture of the gun what it left the factory as.

https://www.atf.gov/firearms/docs/form/annual-firearms-manufacturing-and-exportation-report-afmer-atf-form-530011

The annual report requires the numbers of each type of gun manufactured during the proceeding year, the manufacture is required to maintain the serial number database.  Would you get caught, I can say, can it be checked by the BATF, yes it can and local law enforcement can also do a trace on a firearm, I have had a few BATF trace requests over the years.

Did the seller break the law then by selling it as a receiver?

Did he have knowledge that it had been a rifle to begin with, if so, he should have disclosed it, when I sell parts like lower receivers, I always disclose what it began life as, the lower receiver is the part that is covered under the BATF requirements, it is considered the firearm.   What type of firearm is determine by the records of the manufacture, as you have stated you know it to be a receiver that began life as a rifle, then you would be in violation if you built it into a pistol.

If the seller misrepresented the lower, then he could be hit, but that would be up to the investigator to determine how much of a prick he/she wanted to be and what the intent was.  Got to remember, the BATF determines intent, not your nor the seller.  If for some reason a trace was done on that receiver, saying I didn't know would not make a difference.

If it were me, I would build it into another rifle and pick up another stripped lower receiver to build into a pistol.

Yeah he did disclose it after I asked him after receiving the transfer unfortunately.

What if I took the receiver to an 07 FFL and had them log it in their manufacturing records as a receiver and transfer it to me as a receiver, would that be kosher?

No, once a rifle it is always a rifle in the BATF's eyes, that is how the regulations are wrote and that is how they are enforced, it is listed in the records of Colt as a rifle.  The only thing legally you can do with it, is to apply for a tax stamp as an SBR lower, if you tax stamp it and get approved, you can put any length barrel on it you want.

When a new stripped lower is sold, it is suppose to be listed as "other" on the 4473, if it was known that it was a rifle to begin with, it should have been listed as a rifle on the 4473.

https://www.atf.gov/firearms/qa/if-i-purchase-firearm-and-manufactureremanufacture-it-different-firearm-do-i-need-report

Looks like it can be done, but only by an 07 or 10 FFL. Guess i'll have to find someone with one of those.

Any stripped receiver is properly sold and described as a receiver.  The history of what is has been before isn't important to that description.

If you want to build a pistol you should be well aware of the need to buy a new, unassembled receiver. Colt does not sell stripped receivers.

I know, nor do they make pistols. I just wanted to be the cool kid on the block with a colt pistol. :(

Good luck in finding someone to do it, I am a FFL 07/SOT and I would not do it, I have seen the BATF do to much shit over the years!

There is no such thing as a Colt AR style pistol.

If I have information it was a rifle when it began life, that is what I list when I sell one and have never had a problem with it, but Gamma is correct, listing as a receiver is correct, but again, I have never had a problem with inspections that I have gone through, but I don't sell many guns.

Being the cool kid on the block showing up at the range with a Colt pistol could or would draw attention.

Yeah i'm thinking i'll just turn this into a rifle build for now. I do know a guy in my local gun group with an 07 FFL so I might chat him up about it.

Either that, or just get it stamped, you are not required to use a rifle stock on a registered SBR.

NO that receiver will ALWAYS be a rifle it can never be made into a pistol,  you need to buy another virgin lower and make it into a pistol, you can either sell the one you have but disclose it is a rifle, or build it into a rifle, but in can NEVER be a pistol.