I'm looking to buy a preban and I've got a few questions I hope you can help me with.  I'm looking to buy just a lower so that I can get the exact upper I want, without wasting money on an extra lower that is just going to sit and gather dust.

1. My understanding is that in order for a preban to pass ATF muster should a situation ever arise, I must be able to prove that it was assembled in an AW config prior to Sept '94.  Is this correct?  What is acceptable as proof?  Letter from the manufacturor?  

2. Did Colt sell lowers by themselves, or are they all guaranteed to have been sold as complete guns (thus making them safe to buy just the lower from a legal standpoint).

3. Is there any way to tell which Essential Arms or PWA lowers are forged vs. cast?  How about determining if they were sold as full rifles or just lowers?  Is this why these lowers tend to be so cheap?

I can help you with an answer for your first question..The burden of proof is on you if the ATF questions your AR. A letter from the MFG would be good. I have talked to an ATF tech in DC on more than one occasion. I had asked him that very question. His answer to my asking what constitutes "proof"..... "Whatever you feel comfortable with". Pretty ambiguous 'eh.. Any way thats the answer I got. But your rifle must have been an assembled SAW before the ban...John

Well, it seems to me that a good lawyer could walk into court and put the burden of proof back onto them easily.

Yep, I have talked to these guys on countless occasions, as I am doing an SBR and I dont want any snags etc.etc. If you talk to a local ATF guy you may get an answer totally different than a DC guy. One local guy told me that AWB laws dont apply to SBRs as they are ClassIII!!  Whoa!! glad I didnt build one under that premise. I would have an illegal SAW and an NFA one at that!! Anyway the point I wanted to get across is that you need to check ser.nos. and all other things you can to make sure you are ok... Get answers from ATF in writing if need be.... John

You may be able to answer most of your questions by cruising all of the Legal threads.

But to get you started:
Colt did not sell preban lowers. So any Colt is guaranteed, by serial number, to be preban or postban.

There were only a few makers of complete rifles in preban days. I remember Colt, Olympic, Bushmaster and Eagle. There may be others but I don't personally remember them.

Essential Arms and PWA never made complete guns. Essential Arms are cast, but are very good lowers anyway. Never saw a cast PWA, only forged. They are excellent also.

Proof is whatever you are comfortable with, like the man said.