I was just sitting here wondering about this hypothetical situation:

Suppose you made your own AR lower receiver from a forging or a casting, which is legal by itself, at least in most states.  Suppose you wanted to get cute and put "authentic" Colt M16A2 markings on it, and had the resources (a CNC milling machine, software, and the data file to duplicate the marks) to do it, and actually did make those markings on your lower receiver.

(excluding the serial number, but marked your own identifying number on it instead)

Would this actually be illegal, or just a not-too-bright idea?  Ignoring the Colt trademark and copyright infringement,  just referring to marking your lower receiver as M16A2 (or A1, or M4, whatever), with or without
other markings.

In this hypothetical situation, the receiver would be made in a standard semi-auto configuration and built up into a post-ban
legal configuration.

IF it would in fact be an illegal marking, then
what about those airsoft guns that have exact reproduction Colt markings?  (I hear that some, at least, are Colt-authorized reproductions but have no objective proof of that, but I have one of those airsoft gas guns.   Loads of fun!)

CJ

There's nothing illegal with marking your rifle with any markings you like - provided you are not doing so for an illegal purpose.  You can also use any name you wish, legally, as long as it's not for an illegal purpose... the same principle applies.

You can't copy Colt's trademark without permission, however.  Airsofts with Colt, or HK, or such trademarked markings are not legal for import into this country unless the markings are removed or covered.

You also can't put a serial number on your rifle for the purpose of committing fraud.  You can make up any serial number you like, but doing so for the purpose of duplicating an existing rifle's markings to pull a substitution would be illegal.

That's all about what I figured.  Unless "M16A2" is a copyrighted phrase, you could do it, but I can't really see why you'd WANT to.  I can see that some police would see those markings, seize first, and ask questions later.

As for the airsoft marking issue, it's a fact that there are LOTS of airsoft guns on the market that have such marks.  I have one but I got it second hand.   I have no way of knowing how it got in the country or when.  It was either a bring back or made for the movie trade, because it never had any orange markings on it. I shoot it at various targets in the garage or back yard from time to time for a little legal full auto fun.  On private property, not displayed, nothing illegal, etc...

CJ

I believe M16A2 and M4A3 are all Military Designations and not Colt Trademarks. I heard though that AR-15 was the Armalite Trademark for the AR-15. Armalite sold the rights to the AR to Colt and now, since 25 years have elapsed, the patent has expired on the AR-15, etc...But, trademarks are in effect as long as the Company owning them protects them. For example, Kodak (I believe it was) lost the rights to Polaroid because it let everybody use it, then chose to selectively pursue companies it didn't like. I have never heard of Colt pursuing anybody for using their trademarks, so that might be an issue. If they want to pursue you, they'd have to pursue everybody they know of.