In particular, this CAR-15? We’ll know the answer soon, perhaps. This auction ends today at GunBroker.
The gun in question is a very rare export or commercial XM177E2, a Model 639. The seller explains its history and rarity in the auction:
This auction is for a NEW, NEVER FIRED Colt Model 639 transferable machine gun (the export / commercial version of the XM177E2, or “Commando” CAR-15). I am the second owner. I have a signed, notarized statement from the original owner attesting that  he is the original purchaser and that  the gun is “new, never fired” and  in “factory original” configuration. I will provide the original of that document to the winning bidder plus a similar attestation from me. Original box will also be included.
The gun’s serial number is 4 790 100. The gun’s moderator is registered and stamped with the same serial number (preceded by “SU” for “suppressor”): SU4790100 Having a matching moderator is rare because Colt’s recalled all the moderators (in February 1975) after the ATF ruled that the moderators are sound suppressors and must be registered as NFA weapons in and of themselves. Of the small numbers of Model 639s that had already been sold, many owners complied with the recall and returned their moderators to Colt’s. A few folks resisted, but had to register them as NFA weapons and pay the extra tax stamp. Anyone who purchased a Model 639 after February 1975, or those who returned their moderators during the recall, had to purchase a moderator separately, and thus ended up with a random “ATF” or “IRS” serial number or a random Colt’s number on their moderator.
This gun was manufactured by Colt’s in 1972 (according to a Colt’s representative who ran the serial number for me) and was originally purchased in June 1974 (according to the original Form 3). Recall letters for the XM177 moderators (which had been ruled as suppressors by ATF) went out from Colt’s in February 1975 to previous non-military purchasers of XM177s (according to a gentleman with first-hand knowledge of that effort). The moderator for this gun was registered in October 1975 (according to the original Form 3). (NOTE: This is a two-form, two-stamp gun—one for the gun and one for the moderator.)
NOTE: This is a 5.56mm (.223) rifle-caliber machine gun (the real deal), not the 9mm pistol-caliber version sometimes referred to as Model “639” (NOTE: the 9mm guns are actually roll-marked “SMG”, not “MOD. 639”. They also had bird-cage flash hiders instead of XM177 moderators.).
The gun and moderator are currently at a Class III dealer in Maine and will transfer to your C3 tax-free on two Forms 3.
Entry price: $43,999.00. Buy it now: $44,999.00. But hey, there’s no reserve.
We wish there was a right-side picture, as this appears to be a no-forward-assist gun, making it identical to some of the Son Tay CAR-15s. It’s possibly in the same serial number block as some (the XM177s, though, were in the 9 million block if we recall correctly). The owner presents a statistical analysis extrapolating from known Model 639s that alone is worth the click through. His conclusion:
My personal belief is that Colt’s made S/Ns 4,790,001 through 4,790,100 in 1972 (100 guns total). When 1975 came around and they still had dealers with unsold 639s and they also had to recall all the XM177 moderators, they decided not to make any more “MOD. 639″ guns and just used spare parts from then on to make generic short-barreled M16s (for the commercial, non-military market), with no special roll-mark or special designation, and with a bird-cage flash hider instead of an XM177 moderator. That’s purely conjecture on my part, though.
It’s unlikely a gun like this will move on GunBroker, but it might. More importantly, the GB ad gets word out to the best-heeled among the Class III community that there is a rare and exotic weapon on the market. There’s enough information in the ad for someone to figure out who is the Class III dealer holding the weapon.
We love the CAR-15, but not $45k worth of love. (We’ve never spent that much on a car. Don’t ask about home repairs, though). And we wouldn’t really want a Class III weapon that was NIB unfired… at least, not a rare one that we’d feel obligated to keep in new condition (we’ve bought factory-new SBRs, that’s different). But for a collector of modern MGs who displays rather than fires them, this would be a fine centerpiece.