Wow, looks like I'm the only one who still is a little skeptical about the Mattel story. That's okay, I also believe Oswald acted alone and the Apollo missions really did go to the moon!
I'll lay out the Pros & Cons as I see it.
PRO
1. Colt manufactured only 10 of the 126 components of the M16A1--it's entirely possible that the stocks and handguards were subcontracted to Mattel. Non-traditional weapons makers have indeed been involved with U.S. Rifle production, witness International Harvester making M1's, TRW making M14's, and GM making M16's!
2. The story is too pervasive and persistent not to be true--surely there must be some truth to it. Type in M16 and Mattel into an internet search engine and see how many hits you get!
3. We have eyewitness confirmation of seeing Mattel's trademark inside the stocks. Hard to refute that.
CON
1. Why would a government contractor go to a TOY company? Credibility and the Snicker Factor aside, injection molded thermoplastics for toys is an entirely different technology than foam-filled resin impregnated fiberglass (Fibrite) rifle stocks!
2. Only the Prime Contractors place their trademark and address on M16's. Some parts may be coded with a stamped letter or letters. But of all the subcontractors for the M16, over a 40 year period, not one ever stamped or molded their company's trademark or logo on any of the components they produced. Not one. Oh, except for the Mattel Toy Company. Uh huh.
3. The "first AR stocks" did not have removable buttplates (one sits on my desk as I type this). The buttplates were pressure-fitted and glued on. Unlike the later trapdoor buttplates, they weren't designed to come off. Removing them would damage or destroy the stock. So why would Mattel go to the trouble of impressing a trademark in a location that theorectically was never meant to be seen?
4. SP1 was never a military designation. SP1's were semiautomatic Colt civilian "Sporter" rifles. (The early (1962) rifles sent to VietNam were typically marked as Colt Armalite AR15) I've owned three SP1's. Took 'em all apart. No Mattel logo.
4. The toughest evidence to dispute is the "eyewitness testimony". All I can say is that sincere, honest folks (like the guys who post on this forum) can be mistaken about what they saw thirty years ago. Law Enforcement Officers, lawyers, and psychologists have known for years that the "commonsense" assumption that eyewitness testimony is the best way to get to the truth, is wrong! Witness the many people convicted and incarcerated based on eyewitness testimony, only to be exonerated later by DNA evidence. So all I'm saying is that it's possible to genuinely believe 100% that you said or did or saw something a long time ago (or last week), and still be wrong. Now don't flame me! I'm not saying that anyone is lying! Just saying it's possible to be mistaken. I know I can be. So can you.
So that's why I remain unconvinced of the veracity of the Mattel M16 story. Remember, Torpex inquired as to whether there was a book documenting this story--at this point the answer is no.
I don't discount the heresay and recollections posted so far--they indeed are evidence to be considered. They just aren't sufficient for me.
I have a request in to Colt's Historical Services for any information regarding this question. If/when I hear from them I'll post the answer here.
Meanwhile, here's an address you all might like to visit:
http://www.toyadz.com/toyadz/mattel/m16marauder.html
Now maybe the shooter on the grassy knoll had one of those Mattel M16's, and then it was sent to VietNam to hide the evidence, along with the Beaver, who of course was killed in VietNam...
Eric556