While I agree that a letter carries precious little weight, coupled with the instructions on the 4473 quoted above (post 19), I highly suggest you have a discussion with your ATF examiner.
I have no doubt that you are a man of integrity and that you believe earnestly that you are filling out your 4473's correctly. What you are attesting to in your 4473's when you fill out a complete receiver with a butt stock as "long gun" is that you are transferring a rifle or shotgun. The fact is, you don't know WHAT your customer is going to do with that lower. He could make it a rifle, pistol, shotgun, SBR, SBS or ANY firearm. Of course you have no control over what your customer does with that lower. However, what you are saying is that when it left the shop it was a Title 1 firearm, when clearly that is not the condition of the firearm when it leaves the shop.
Please READ the 4473 instruction section and call your examiner for clarification.
Last edited by rjrivero; February 20, 2012 at 10:29 AM.