I read through some of the legal info threads posted above, and I think I have things correct, but I just want to make sure...

Say a guy I know () wanted to build up an AR pistol.  This guy happens to have a couple of lower receivers that he bought stripped.  Both of these lowers are now built up with LPK's and both also have rifle stocks attached.  That' s it.  No upper of any kind have ever touched these lowers.

These stripped lowers were purchased about ~2 years ago, and he is about 90% certain they were checked as 'receivers' on the 4473 at FFL.

This guy has several other complete AR's, all rifles.  No other loose uppers of any kind, or barrels or anything like that.  Just a bunch of complete rifles, and some lowers with stocks.

Could he take one of those lowers and remove the stock, and build it up into a pistol?

Or would he be better off just buying a new, stripped lower and starting from scratch?  He wants to make sure he is 103% legal on how he does this.

Not sure if it matters or not, but this guy is also currently in the process of obtaining a SBR.  Though it hasn't even progressed to the point of submitting paperwork just yet, but very soon.  He has a Trust.  The pistol in question here would probably be built either during, or after paperwork was submitted for the SBR.   Again, not sure if this would pertain at all.

Thanks gents.  

Tell the guy you know to be quiet and stop asking permission. Theoretically, if nobody saw the stocks attached- who's to say they havent always been pistols?

Understood.  I guess I was just looking for some reassurance that it simply doesn't matter even if it was known, because there was never an upper attached.... but point taken.  Thank you.

Never had a BARRELED upper installed, even though a butt stock is current installed? It is still just a receiver. Make it into whatever non-NFA item you want.

You can make it into a pistol simply by removing the butt stock and installing a barreled upper with a barrel under 16". HOWEVER, do not have that removed butt stock in your possession unless you also have an unused 16"+ upper you can install. You can reconfigure the pistol into a rifle with the proper sequence of changes, and back again into a pistol.

An attached stock on a receiver means nothing. Until it is a rifle or shotgun, "it is still not yet a rifle or shotgun and therefore an other." Its's still a receiver until it's built into something. It doesn't matter what it can be, only what it is right now. Until it's a complete rifle it's not a rifle buttstock or not.

Or what Scollins just typed.

Thank you for the info guys, now I feel better.

A pistol can become a rifle, but a rifle can't become a pistol (unless you SBR it).

I had the same question. I have a striped lower I would like to build into a pistol. Since firearms are not registered in WA and its never been a rifle or anything other than a receiver I'm clear to proceed with my build. Thanks for the clarification.