I have a Colt upper receiver assembly in mint condition from the 1960's. No forward assist and no brass deflector.  Color is green to dark gray. The barrel is marked "C MP C", and it has a A1 flashhider. I also received the original butt stock and pistol grip. I recently purchased a Colt slab side Chrome carrier with no bolt.
MY Questions:
What bolt do I need? Chromed or parkerized?
Lower receiver, what is correct, partial fence or no fence?
Thanks

Ditch the A1 flash hider and get a 3-prong.  Troy is correct, you have an original M16, not an M16A1 upper.  I believe a slab-sided lower (no mag fence) would be correct on this gun.  Hopefully, Colt-653 will make some of those available to us sometime soon.  See this thread if you don't know what I'm talking about.

The chrome plated chamber (indicated by the second "C" stamped on your barrel) came into being in May of 1967.  By this time, the rifles had been standardized with:
- Third pattern lower receivers, with full magazine fence
- Parkerized bolts and carriers
- Sturtevant buffer

Ditch the A1 flash hider and get a 3-prong

Why, It has the original FH on it now! It is a Model 604 Air Force upper.

What are the dates these Air Force rifles were built?

Thank You

Quoted: The chrome plated chamber (indicated by the second "C" stamped on your barrel) came into being in May of 1967.  By this time, the rifles had been standardized with: - Third pattern lower receivers, with full magazine fence - Parkerized bolts and carriers - Sturtevant buffer

I dont think that is correct about the chrome chamber.  Fully chromed bores first appeared on the M16A1 in 1967.  Barrel should be marked C MP B or C MP CHROME BORE

The XM16E1 has a chrome chamber only. C MP C

Scott

In NEW condition. Had the cardboard in the barrel when I got it.





Thanks for the help

I am a bit confused, not sure if you want to build a Air Force Colt's Model 604 (M16), or a US Army Model 603 (M16A1).  Any how, they both used the same bolt group when your barreled upper was made (1967-71?).  They had two carrier key stakes, parked, no marking on the carrier, forward assist cuts, no extractor buffer, long HD extractor spring, and MP marked bolts, you can get one from this guy:  

www.auctionarms.com/search/displayitem.cfm?itemnum=6470646

I have a couple of these bolt groups, they are the real deal and no doubt came out of 604 uppers like yours (some might be out of late 602's though).

Far as the lower goes, the mag fence came out prior to the C MP C barrels.

Quoted: I am a bit confused, not sure if you want to build a Air Force Colt's Model 604 (M16), or a US Army Model 603 (M16A1).  Any how, they both used the same bolt group when your barreled upper was made (1967-71?).  They had two carrier key stakes, parked, no marking on the carrier, forward assist cuts, no extractor buffer, long HD extractor spring, and MP marked bolts, you can get one from this guy:   www.auctionarms.com/search/displayitem.cfm?itemnum=6470646 I have a couple of these bolt groups, they are the real deal and no doubt came out of 604 uppers like yours (some might be out of late 602's though). Far as the lower goes, the mag fence came out prior to the C MP C barrels.

Thank You everyone for the responses.

At first I wanted to build this rifle as close to it's configuration when it was made. I did not know much about it and you all helped! I am surprised to see that it was originally equipped with a forward assist type bolt carrier. As I mentioned above I purchased a NOS slab side chrome carrier I wanted to use. Although it may not be correct I may still use it, (it would look better!!).
I will wait for a receiver from Colt-653 that hopefully will match this upper assembly, BUT still am not (completely) sure which style I need??

Again, Thanks for all the information on this upper!

By the way, Is it possible the barrel is chrome lined? The seller thought it was??

M16 clone TOP, showing original Lt weight edgewater buffer and slabside bolt carrier
XM16E1 clone bottom, M16 stock, 3 prong FH , Chrome carrier,FWD assist

M16A1 clone, birdcage FH, fenced A1 lower, A1 butt stock shown.

see the differences ??

How to tell if it's chrome lined

Quoted: I will wait for a receiver from Colt-653 that hopefully will match this upper assembly, BUT still am not (completely) sure which style I need??

The lower that upper came off of had a mag fence.  Same lower Colt's was using on the M16A1.  Earlier Air Force rifles such as the 601 and 602 did not have the mag fence, and also lacked chrome chambers, along with other features....

Quoted: I am surprised to see that it was originally equipped with a forward assist type bolt carrier.

Colt's talked the Air Force into accepting carriers with the forward assist cuts in 1966.  Colt's did not want to make two types of carriers anymore.

Quoted: By the way, Is it possible the barrel is chrome lined? The seller thought it was??

No, C MP C means, Colt, Magnetic particle inspected, Proof fire, chrome Chamber.

Tag

Here is a Air Force Model 602 clone I had:



These earlier Air Force rifles did not have the mag fence.  Earlier ones had chrome bolt/carriers.

Barrels were proofed marked by the front sight base (note FSB is different):



Barrels were marked "12" to differentiate them from the earlier Model 601 1/14 twist barrels (this is also the same barrel used on the XM16E1):

Is the model 604 a mag fenced lower, with a slab side upper?  What are some other details on the 604?  

Quoted: Is the model 604 a mag fenced lower, with a slab side upper?  What are some other details on the 604?

Purdy much.  It is the same rifle the Army was getting at the same time, except the Army got the forward assist and called their rifle the M16A1.  The 604 was the later M16 delivered to the Air Force.  Think the 614 was the commercial version?  Any how, there are lots of variations, but a stereotypical 604 would have a "M" and "12" marked barrel, or more likely a C MP C marked barrel, bird cage flash hider, parked MP marked bolt with no extractor buffer, unmarked carrier with assist cuts, upper with no forge code, now standard recoil spring buffer, hole drilled in buttstock screw, no trap door buttstock with rear sling swivel on a hinge, etc.............

I think we're getting into a certain amount of nomeclature confusion with the USAF end of things.

The USAF adopted either the Colt 601 or 602 (I can't remember which for some reason, and since my other comp is in the shop I can't consult my chart) as the AR-15.  They later adopted the 604 as the M16.  The US military used the E1/A1 bit to differentiate between rifles with and without forward assists.  You see this with the XM16/M16 and XM16E1/M16A1, as well as, with the XM177 and XM177E1.  Interestingly enough in both cases the Air Force guns, come second in the Colt numbering system.  603 being the XM16E1/M16A1 and the 604 being the XM16/M16, while the 609 is the XM177E1 and the 610 is the XM177.

The 603 and 604 are, as far as I know, identical with the exception of the forward assist.  They should both exist in iterations with either the Type 1 Duckbill FH, the Type 2 Duckbill FH, or the birdcage/A1 FH.  Later variants of both rifles should have standardized on the usage of the birdcage/A1 FH.

Also the 614 was the export/commercial version of the 604.

Quoted: I think we're getting into a certain amount of nomeclature confusion with the USAF end of things.

I thought we were doing OK?

Quoted: The USAF adopted either the Colt 601 or 602 (I can't remember which for some reason, and since my other comp is in the shop I can't consult my chart) as the AR-15.

Well kinda, the Air Force adopted the AR-15, and named it the XM16/M16.  First Colt's delivered 601's, then 602's, and then 604's, but they were all US Air Force XM16/M16's.  Colt's production was updated as the Army put in "requests" for changes, and Air Force production was updated too.

Quoted: The 603 and 604 are, as far as I know, identical with the exception of the forward assist.  They should both exist in iterations with either the Type 1 Duckbill FH, the Type 2 Duckbill FH, or the birdcage/A1 FH.  Later variants of both rifles should have standardized on the usage of the birdcage/A1 FH.

Yes, 603 and 604 were the same save the FA.  Neither was made with the first type duck bill flash hider, those were phased out right before the transition from 601 to the 602.

Quoted: Also the 614 was the export/commercial version of the 604.

Thanks, I thought so, do not have a book handy.

Quoted: Quoted: Is the model 604 a mag fenced lower, with a slab side upper?  What are some other details on the 604?   Purdy much.  It is the same rifle the Army was getting at the same time, except the Army got the forward assist and called their rifle the M16A1.  The 604 was the later M16 delivered to the Air Force.  Think the 614 was the commercial version?  Any how, there are lots of variations, but a stereotypical 604 would have a "M" and "12" marked barrel, or more likely a C MP C marked barrel, bird cage flash hider, parked MP marked bolt with no extractor buffer, unmarked carrier with assist cuts, upper with no forge code, now standard recoil spring buffer, hole drilled in buttstock screw, no trap door buttstock with rear sling swivel on a hinge, etc.............

Ekie, I am going to disagree a bit with your idea of the stereotypical M16.  From what I can discern, most the rifles the Air Force ordered were delivered fairly early on, before many of the changes usually associated with the M16A1 were made.  While I have no doubt that some rifles were delivered in the configuration you describe, I believe that many, and probably most, M16s were delivered as:

-Type 2 lower receiver (pivot pin retaining boss, no mag fence)
- 1:12 twist barrel, no plating
- Type 2 three prong flash hider
-Chrome plated bolt carrier with no forward assist cuts
-Edgewater buffer

I base this on a statement in TBR, pg. 226, which notes that at the time that the Air Force agreed to accept serrated bolt carriers, they already had 136000+ M16s in their armouries.  I don't know how many they bought in total, but this has to represent the lion's share.

Quoted: Well kinda, the Air Force adopted the AR-15, and named it the XM16/M16.  First Colt's delivered 601's, then 602's, and then 604's, but they were all US Air Force XM16/M16's.  Colt's production was updated as the Army put in "requests" for changes, and Air Force production was updated too.

Not according to my information.  You'll notice that in Air Force inventory documentation, they have seperate fields (and NSNs) for their AR-15 and their XM16/M16.  Find a copy of AF Instruction 36-2226 or 36-2226 Supplement 1 to see what I'm talking about.  The 601/602 rifles in the USAF were designated AR-15, the 604s were designated M16.  Just checked, I guess not all of them have the AR-15 listed, but I distinctly remember it being seperate in at least one of the versions of the document.

Quoted: Ekie, I am going to disagree a bit with your idea of the stereotypical M16.

That's fine, but I never defined a "stereotypical" M16.  The subject at hand was Screech's 604 project, I went on to describe:

Quoted: ......but a stereotypical 604 ............

Quoted: -Type 2 lower receiver (pivot pin retaining boss, no mag fence) - 1:12 twist barrel, no plating - Type 2 three prong flash hider -Chrome plated bolt carrier with no forward assist cuts -Edgewater buffer I base this on a statement in TBR, pg. 226, which notes that at the time that the Air Force agreed to accept serrated bolt carriers, they already had 136000+ M16s in their armouries.  I don't know how many they bought in total, but this has to represent the lion's share.

Hmm, and on top of that, the rifle you describe Thatguy96 says is actually an AR-15, and not a M16.

Quoted: Not according to my information.  You'll notice that in Air Force inventory documentation, they have seperate fields (and NSNs) for their AR-15 and their XM16/M16.  Find a copy of AF Instruction 36-2226 or 36-2226 Supplement 1 to see what I'm talking about.  The 601/602 rifles in the USAF were designated AR-15, the 604s were designated M16.  Just checked, I guess not all of them have the AR-15 listed, but I distinctly remember it being seperate in at least one of the versions of the document.

No kidding, I thought the Air Force was buying XM16/M16 rifles that whole time.  Well, got to admit, I am going to have to hit the books on that one.......

OK, I looked it up, the 601 was an AR-15, the first US Air Force manual (page 108 of TBR) is called "RIFLE, AR-15", and has a picture of a 601 on the cover.  First real mention of the name M16 seems to be contract 508 awarded November 4th 1963.  So, it would seem to me that the 601 was an AR-15, and the 604 was a M16.  Not sure where the 602 falls in, because some were delivered before and after contract 508.

Thanks Thatguy96, for the heads up, never noticed that before.

np, this is what I do hehe.

My work

Did not know that was you, thats cool.  Here is mine, different rifle though:

www.tantal.kalashnikov.guns.ru/variants.html

Would like to do one on the US AR-15/M16, but all those parts are expensive, and takes allot of time, figure someone else can do it.

Hehe, now its my turn to say "That's you?"  Awesome.

In the beginning, there was the Armalite AR-15. Then Colt bought the rights to the AR-15, so there was the Colt Model 601.
The Model 601 was either the AR-15 or the Armalite AR-15. The USAF, ARPA, and Navy SEALs purchased AR-15s.



There was an evening and a morning. Then the United States Air Force made a purchase of 8,500 AR-15, large enough it got "Property of U.S. Goverment" marks. This was the Model 602, though it was still an AR-15.


McNamara said, "Let the whole military buy AR-15s", and in November 1963, Contract 508 was awarded to Colt, and the Model 603 XM16E1 and Model 604 Colt M16 were born. Over the years, many changes were made to the Models 603 and 604, like the birdcage flash hider in January 1967, but they still remained Models 603 and 604.

Page 226 of The Black Rifle specifically says,
"On 9 August 1967 the Air Force reported that they had 136,506 M16 rifles on inventory, and that all their units fighting in Vietnam were now M16-equippeed. One of the last modifications to the M16 had been Air Force acceptance of the serrated M16A1 bolt carrier, which altough useless per se in the m16 did have the decided advantage of eliminating plain, un-serrated carriers as an item of manufacturer and issue." However, this was not all of the M16 purchases. The 116,695 M16s ordered in Contract 508 and 28,580 M16s purchased in Contract 0018 would be about half of the USAF's M16 purchases during the Vietnam war. Contract 021 in 1968 for 136,001 M16s and Contract 0001 in 1969 for 65,000 M16s would account for the other half.

To return to the original subject, as already noted, the barrel is marked "C MP C", which means Colt, Magnetic Particle Inspection and Proof Tested, Chrome Chamber Only. The chrome chamber was adopted after May 1967. The birdcage flash hider was adopted after January 1967. Therefore, I would say you would want a later Model 604 M16, which means partial fence and parkerized carrier. Chrome plated bores appeared after 1971.

BTW, The Black Rifle considers the XM16E1 to be the Model 602, so any reference to a Model 01 in The Black Rifle could either be a Model 601 or Model 602.

Quoted: Hehe, now its my turn to say "That's you?"  Awesome.

Flattery full circle, hehe.

Very nice synopsis pettifogger.  The visual aids are a great touch.

Quoted: BTW, The Black Rifle considers the XM16E1 to be the Model 602, so any reference to a Model 01 in The Black Rifle could either be a Model 601 or Model 602.

Ezell was the man, but he was human.

Man, I really need to break down and buy some books.  As it stands now, every time something like this comes up in the project I rely more or less on Pettifogger to check it against them and more or less type out the passages.  While I appreciate it, I really should be able to do it myself heh

This is so tagged. What books do you gentlemen consider indispensible for the tracing of the early history, besides Ezell's The Black Rifle? I too have enough early parts to consider a 601 or 602 forgery. Are there any sources for the Edgewater buffers left? TIA, and damn fine work all around!

Quoted: Man, I really need to break down and buy some books.  As it stands now, every time something like this comes up in the project I rely more or less on Pettifogger to check it against them and more or less type out the passages.  While I appreciate it, I really should be able to do it myself heh

Quoted: This is so tagged. What books do you gentlemen consider indispensible for the tracing of the early history, besides Ezell's The Black Rifle? I too have enough early parts to consider a 601 or 602 forgery. Are there any sources for the Edgewater buffers left? TIA, and damn fine work all around!

Don't know where to get a Edgewater.  Yep, need to at least get TBR.

Quoted: They later adopted the 604 as the M16.

Quoted: The 601/602 rifles in the USAF were designated AR-15, the 604s were designated M16.

Quoted: McNamara said, "Let the whole military buy AR-15s", and in November 1963, Contract 508 was awarded to Colt, and the Model 603 XM16E1 and Model 604 Colt M16 were born.

OK, now I still have one detail to hash out with you two.  My understanding was that the bulk of the XM16 rifles delivered under contract 508 (Nov 63 - Jan 67) were 602's, and not 604's.  The rifles delivered to the Air Force during that contract are as BattleRife described:

Quoted: -Type 2 lower receiver (pivot pin retaining boss, no mag fence) - 1:12 twist barrel, no plating - Type 2 three prong flash hider -Chrome plated bolt carrier with no forward assist cuts -Edgewater buffer

And they looked something like this:



Arguably these rifles were XM16's, and not AR-15's (although they did say AR-15 right on the side).  So, I already conceded that the 601 was not a M16, but at this point I maintain that the bulk of the XM16's delivered under contract 508 were 602's, not 604's.

Thanks for all the great help and information. A couple questions:
I have this book:
The Black Rifle
by R. Blake Stevens & Edward C. Ezell

Is this book worth buying?
BLACK RIFLE II - The M16 Into the 21st Century
by Christopher R. Bartocci

Also: What slings were used on these rifles?

Quoted: OK, now I still have one detail to hash out with you two.  My understanding was that the bulk of the XM16 rifles delivered under contract 508 (Nov 63 - Jan 67) were 602's, and not 604's.  The rifles delivered to the Air Force during that contract are as BattleRife described: Quoted: -Type 2 lower receiver (pivot pin retaining boss, no mag fence) - 1:12 twist barrel, no plating - Type 2 three prong flash hider -Chrome plated bolt carrier with no forward assist cuts -Edgewater buffer Arguably these rifles were XM16's, and not AR-15's (although they did say AR-15 right on the side).  So, I already conceded that the 601 was not a M16, but at this point I maintain that the bulk of the XM16's delivered under contract 508 were 602's, not 604's.

I do not have my copy of TBR right beside me, since I am posting from work (which I should definitely NOT be doing) but I never saw things as being protrayed this way.

The Colt 601 was essentially a commercial gun, and though various US military agencies bought it for various reasons, it never had official status.  It was the Colt (Armalite) AR-15, "local procurement"

The Colt 602 I have never fully understood.  I have never been able to tell what changed between the 601 and the 602, or who bought the 602.  My only theory is that since the rate photos of them all seem to show US property marks, that they were the 8500 rifles bought by LeMay in early 1963, and maybe incorporated the extra three ounces of steel in the barrel demanded after the water-in-the-bore issue arose.  Regardless, still essentially an off-the-shelf commercial item.  No official US catalogue codes.

It is my strong impression that once the AR-15 system was officialized by contract 508, everything got new numbers.  The Colt rifles 603 and 604 were the US DoD items XM16E1 and M16 respectively, and all rifles delivered under this contract fell into one of these two descriptions.  Any 602s delivered in this period should have been residuals from an earlier deal, and not part of the official "one-time buy" (contract 508).  

Does TBR really suggest that the XM16E1 was the 602?  I never got that idea, but I have known the truth longer than I have owned the book, so I may have just glossed over it.

I also am perpetually confused by the term XM16.  No book I have ever refers to such an animal.  The USAF went from commercial procurement of the (602) AR-15 to the M16: there was no transition.  I could see that some historians might, after the fact, refer to the purchase of the 602 as the XM16 since, looking back, we now know that was where they were headed, but I still doubt that the term was ever official.

From pettifogger:

To return to the original subject, as already noted, the barrel is marked "C MP C", which means Colt, Magnetic Particle Inspection and Proof Tested, Chrome Chamber Only. The chrome chamber was adopted after May 1967. The birdcage flash hider was adopted after January 1967. Therefore, I would say you would want a later Model 604 M16, which means partial fence and parkerized carrier. Chrome plated bores appeared after 1971.

I agree with all your premises, but not the conclusion.  By your own data, our (now very confused) original poster should be building a post May '67 model 604.  I believe all rifles transitioned from partial fence (retaining boss only) to full fence in February '67.  Therefore he should have a full fenced (type 3) receiver.

Quoted: The Colt 601 was essentially a commercial gun, and though various US military agencies bought it for various reasons, it never had official status.  It was the Colt (Armalite) AR-15, "local procurement"

Kinda getting into semantics here.  There were close to 20,000 delivered.

Quoted: The Colt 602 I have never fully understood.  I have never been able to tell what changed between the 601 and the 602, or who bought the 602.

The 602 is the rifle you offered up as being a "stereotypical M16".  They were purchased by the Air Force from about 1963 to 1966.  Without going into great detail, or addressing every variation, "in general" a 602 has the following features that the 601 lacked (borrowing some of your prior post):

1/12 twist
Type 2 lower receiver (pivot pin retaining boss, no mag fence)
Type 2 three prong flash hider
black impregnated plastic furniture
T charging handle

Quoted: My only theory is that since the rate photos of them all seem to show US property marks, that they were the 8500 rifles bought by LeMay in early 1963, and maybe incorporated the extra three ounces of steel in the barrel demanded after the water-in-the-bore issue arose.  Regardless, still essentially an off-the-shelf commercial item.  No official US catalogue codes.

These 602's were not "off-the-shelf", considering the bulk of them were purchases under contract 508.  Nothing unofficial about that contract.  Also note (this is more for the other two guys) that the Hughes book has a picture of a August 1963 Air Force manual that is titled M16.  This M16 (602) rifle was in use more then three years before the 604 went into production.

Quoted: It is my strong impression that once the AR-15 system was officialized by contract 508, everything got new numbers.  The Colt rifles 603 and 604 were the US DoD items XM16E1 and M16 respectively, and all rifles delivered under this contract fell into one of these two descriptions.  Any 602s delivered in this period should have been residuals from an earlier deal, and not part of the official "one-time buy" (contract 508).

If the M16 nomenclature come into being at or after contract 508, and if the 604 did not have a full mag fence, then I could go along with that.  But, that is not the case.

Quoted: Does TBR really suggest that the XM16E1 was the 602?  I never got that idea, but I have known the truth longer than I have owned the book, so I may have just glossed over it.

Well, off the top of my head, there is this weird rifle in the book, it looks like a 603 upper on a 601 lower, and the caption hints it is a 602.  Think it might be picture 139?

Quoted: I also am perpetually confused by the term XM16.  No book I have ever refers to such an animal.  The USAF went from commercial procurement of the (602) AR-15 to the M16: there was no transition.  I could see that some historians might, after the fact, refer to the purchase of the 602 as the XM16 since, looking back, we now know that was where they were headed, but I still doubt that the term was ever official.

I have used that term, but have never seen it in print.  We had a AR-15 (serial number 5X,XXX) in the armory that had been restamped many times.  It looked like it had been stamped XM16, then stamped out, and stamped XM16E1, stamped out, and then stamped M16A1.  Hard to read with all the XXXXX's all over the lower.

Quoted: I agree with all your premises, but not the conclusion.  By your own data, our (now very confused) original poster should be building a post May '67 model 604.  I believe all rifles transitioned from partial fence (retaining boss only) to full fence in February '67.  Therefore he should have a full fenced (type 3) receiver.

I am with you on this one, Screech's rifle was a 604, and originally had the mag well fence.  Guess I need to post some 604/614 pics so he can get a better idea.

OK, Here is a “stereotypical BattleRife M16", the type delivered to the Air Force from say 63-66 or so.  Would think it safe to assume it is a 602 (EDIT: that is probably a early 604):



Here is a 614, and marked as such.  Same thing as a 604 except the markings:

You know, it might full well be the case that the only real difference between the 601 and the 602 is the change in the charging handle.  From everything else I've seen they're identical in every other respect.

OK, I just found more info on the 604, will have to post it later.  But, looks like you guys were largely correct on this one too.

Regardless, because Screech's barrel has a chrome chamber, the rifle his lower came off of would be like the 614 pictured above (with mag fence).

Quoted: Did not know that was you, thats cool.  Here is mine, different rifle though: www.tantal.kalashnikov.guns.ru/variants.html Would like to do one on the US AR-15/M16, but all those parts are expensive, and takes allot of time, figure someone else can do it.

Damn. That was very good stuff.

Your stock just went up.

It's the internet and difficult to measure a posters point of reference/experience.

That helps.

Quoted: You know, it might full well be the case that the only real difference between the 601 and the 602 is the change in the charging handle.  From everything else I've seen they're identical in every other respect.

Man, wish it was that simple, but take a look at the Model 02 pictured at top, it has the old charging handle.

Yeah, I looked at the picture after I posted that, no such luck.

Quoted: Quoted: Did not know that was you, thats cool.  Here is mine, different rifle though: www.tantal.kalashnikov.guns.ru/variants.html Would like to do one on the US AR-15/M16, but all those parts are expensive, and takes allot of time, figure someone else can do it. Damn. That was very good stuff. Your stock just went up. It's the internet and difficult to measure a posters point of reference/experience. That helps.

Thanks.  I tell you what, that AK-74 variation guide started just like this thread.  With a couple of guys batting the type info of you can't find neat and packaged in a book back and forth.  There were plenty of dead end ideas, misconceptions corrected by the other guy, weird variation rifles that lead no where, and so on.  If you were to read that first thread, you would wonder how any coherent info would ever come out of it.

Anyhow, apparently the 604 was an Air Force only item.  Unlike the 601 and 602's which are floating around every where.  So finding detailed info, pics and such was a real bear.  There are no close up receiver pics of a 604 that I could find in any of the books or the net.  Apparently the MOD Tool Room doesn’t even have one.  I had been operating under certain assumptions on what the rifle was, and was wrong.  But, Reed Knight has one, will post up details later, gotta read to the kids, tuck them in, you know, the important stuff before I can write another big post.

Quoted: Yeah, I looked at the picture after I posted that, no such luck.

It gets worse, I know of 601's with the pivot pin retaining boss and 602's without it.  I suspect Colt's is like Izhmash, and does that stuff on purpose LOL!

My huge project, even with the amazing help of people like Pettifogger and D.E. Watters, won't be complete anytime soon, but if anyone has webspace and the where-with-all, I'll be happy to help and write up stuff if needed for more specific things like this.

The Model 602 is an AR-15. It's marked Colt AR-15.
The Model 604 is a M16. It's marked Colt M16.

Contract DA-11-199-AMC-508, which was awarded on 4 November 1963, had its initial delivery in March 1964 and its final delivery in September 1966. The contract was for XM16E1s and M16s, not XM16E1s and AR-15s.

According to page 134 of The Black Rifle

The basic procurement contract called for 104,000 rifles: 85,000 with the Colt-designed bolt assist, designated the XM16E1, for the Army and the marines at a base unit of $121.84; and the remaining 19,000, called simply the M16, for the Air Force at a flat $112.00 each.

On page 149 of The Black Rifle

The first true M16, meaning the first rifle procured for the Air Force under the combined four-Service ``One-time buy'' (contract ``508'') was presented by Colt's to USAF Major General E.J. Gibson at a ceremony at the historic Hartford plant on march 30.

R. Blake Steven and Edward Ezell's The Black Rifle quite definitely refers to the XM16E1 as a Model 602.

On page 131, a photo is captioned:

137. An early Colt model (6)02 (XM16E1) showing the bolt closure and modified charging handle contour, but still fitted with the early chromed bolt and original ``heavy'' firing pin.

On page 135, the following photo is captioned:

140. Closeup of the receiver markings on a Colt AR-15 model (6)02, the precursor to the XM16E1, serial no. 21304. Black-impregnanted furniture, redesigned charging handle, 1-in-12 rifling, modified bolt release, and ``type 2'' flash suppressor.

On page 157, a photo is captioned:

150. Above: a Colt factcory ``cutaway'' of an AR-15 (XM16E1) model 02.

OK, I see that pettifogger has a copy of SMALL ARMS TODAY, and I assume you have Small Arms Review (SAR) Vol. 1 No.'s 4-9.  So don't think my library is any more expansive.  Here is some quick info, nothing totally inclusive or irrefutable.

Colt's Model 01 (601), marked and purchased by the Air Force (among others) as the AR-15:

serial numbers 000101-015,XXX?

Colt's Model 02 (602), marked AR-15, purchased by the Air Force:

serial numbers 020,XXX-039,XXX?

Colt's Model 604, marked AR-15 and M16, purchased by the Air Force exclusively

serial numbers 04X,XXX thru I don't have a clue.

In SAR Vol. 1 No. 5 on page 68 there is described a Colt's 604 (from the Reed Knight collection):

"Air Force contract M16's were the model "04", and the designation was in the serial number range - starting with "04".  The Air Force did NOT want a forward assist on their M16's, and initially there were bolt carriers made that did not have the serrations.  Eventually, this separate carrier was dropped in the interest of standardization of parts, so either carrier can be correct."

And, according to Duncon Long, hehehe, just a bit of humor.

Unless the 602 has a forward assist (from what I remember it doesn't) then it shouldn't be an XM16E1.  The E1/A1 was supposed to denote the precense of a forward assist.

Quoted: The Model 602 is an AR-15. It's marked Colt AR-15. The Model 604 is a M16. It's marked Colt M16.

Maybe so, but Model 604 serial number 040123 is marked both Ar-15, and M16.  So which is it?

Quoted: Contract DA-11-199-AMC-508, which was awarded on 4 November 1963, had its initial delivery in March 1964 and its final delivery in September 1966. The contract was for XM16E1s and M16s, not XM16E1s and AR-15s.

I think we can all agree on that, even if Colt's stamped some of them AR-15.

Quoted: On page 149 of The Black Rifle The first true M16, meaning the first rifle procured for the Air Force under the combined four-Service ``One-time buy'' (contract ``508'') was presented by Colt's to USAF Major General E.J. Gibson at a ceremony at the historic Hartford plant on march 30.

So the rifle the Air Force referred to as the M16 prior to March 30, 1964, and even printed a manual for the M16 in August 1963, were not really M16's?  I am not sure what to make of this. The Air Force referred to the AR-15 as an M16 as far back as August 1963, but deliveries were not made until 1964?  Really, this AR-15 vs M16 is simply semantics.

Quoted: On page 131, a photo is captioned: 137. An early Colt model (6)02 (XM16E1) showing the bolt closure and modified charging handle contour, but still fitted with the early chromed bolt and original ``heavy'' firing pin.

Quoted: Well, off the top of my head, there is this weird rifle in the book, it looks like a 603 upper on a 601 lower, and the caption hints it is a 602.  Think it might be picture 139?

So I was off two pictures?  Going to have to go "by the book", and not by memory with this crowd, LOL (that is one wierd rifle though).

Quoted: On page 135, the following photo is captioned: www.stwing.upenn.edu/~wcchang/M16/M602.jpg 140. Closeup of the receiver markings on a Colt AR-15 model (6)02, the precursor to the XM16E1, serial no. 21304. Black-impregnanted furniture, redesigned charging handle, 1-in-12 rifling, modified bolt release, and ``type 2'' flash suppressor.

I will go with Ezell on that one, the 602 was certainly the "precursor" to the XM16E1 in every sense of the term.  Kinda wierd that it mentions the rifle has the new charging handle, when it don't.

Quoted: On page 157, a photo is captioned: 150. Above: a Colt factcory ``cutaway'' of an AR-15 (XM16E1) model 02.

Yeah, that is the other messed up photo description I noted in TBR.  The rifle on top is actually a late (post 66) M16 Model 604, and don't look nothing like a Model 602.

Quoted: Unless the 602 has a forward assist (from what I remember it doesn't) then it shouldn't be an XM16E1.  The E1/A1 was supposed to denote the precense of a forward assist.

Correct

FWIW:  SAR had an article devoted to the 602 around two to three years ago.  I believe it is the same issue that has an interview with L. James Sullivan.

I'll need to dig through my back issues to find it.