Hi,

tried to do some google searching but my results came back with nothing of help.

Question: If you buy an hk33 receiver flat and it comes with a manufacturers name and model stamped what are your options for building it? Item has no serial number on it.

Reason I ask is a gunsmith says that I wasted my money because it is illegal for anyone to build up a receiver that has another companies name and model stamped on it.

Not illegal at all, though if you are a licensed manufacturer, you are ALSO required to stamp your name and model information, etc on it.  No such requirement for an unlicensed maker, except under the purview of the NFA.

If you want to build from a pre-stamped flat, you can obscure the marks if you want (not a firearm now, so no problem removing erroneous marks), or leave them there and build as you will.  There may be state or local laws which would complicate things, but none that I know of federally, or in Colorado, where I reside.

<-- 07/C2 FFL

Send him the links to the US Code and CFR's that regulate firearms, and ask for a cite.  He'll be looking for a long time, because it isn't there.