I don't want to get into the merits of whether or not A2s are considered retro, but I believe someone mentioned there was a picture (maybe in Small Arms Review?) of an experimental A2. I think it might've had an A1 buttstock/grip and maybe even an A1 barrel. I never saw the picture, but I'd like to hear some more about it and would appreciate a picture if someone has one. Thanks fellows.

there is a picture of the experimental A2s in one of the "are A2s retro" threads

I found what you're talking about. It's a picture of some of the prototypes from a museum. Interesting stuff. Looks like most of the prototypes had teardrop forward assist and an A1 port door. Hmm... I can't tell if all of them had A2-length buttstocks or not. Anybody have any more info?

I have the SAR issues covering the Colt ID Guide, I will scan and post the pic this weekend for you.

That would be incredible! I'm thinking I want to build an M16A1E1 clone. To heck with all you naysayers who say the A2 ain't retro.

An XM16A1E1, even with those new-fangled A2 type sights, is still an A1 isn't it...

Yep, and by simply changing the pistol grip, I can use it to compete in NRA Highpower. At any rate, I have a gray A2 upper on the way - it's preban gray, so it won't match my NDS-16A1 - but we'll see how it goes. Looking forward to seeing those pics from RMiller.

Yes, but an M16A1E1 was a transitional model, basically an A1 with the new A2 furniture and FA. Model 711 I believe...

Morg, I don't think the 711/715 got the M16A1E1 moniker. It was my understanding, based in particular on the Rock Island photos and the limited research I have done, that the M16A1E1 was the experimental name given the new model with new sights, the gov't profile barrel, new handguards, and new twist rate, which was adopted shortly after as the M16A2. That said, I could be wrong and look forward to more pictures/info.

1987

The way the US Army nomenclature system works is that experimental subvariants of experimental or standard items are assigned an E with a number in arbitrary sequence beginning at one (just like standard A numbers).  When a E model is adopted, it is assigned the next A number in sequence.

M16 is one of many exceptions, as the usage of XM16 was sort of retroactive and more of a paper designation than anything else.  Therefore you can start from XM16E1 knowing that there was an M16 and get the whole run of standard A models:

XM16E1 = M16A1

M16A1E1 = M16A2

M16A2E3 = M16A3

M16A2E4 = M16A4

The M16A1E1 grew out of a product improvement program (PIP) and the early M16A1 PIPs were essentially just M16A1s with A2 furniture.  The addition of the 1:7" barrel, Burton bump, LMG sights, receiver reinforcements, and round forward assist came later on rifles by that time designated M16A1E1, and then adopted as M16A2s.  Note that the M16A2, M16A2E1 and M16A3 are actually all in the 600 series (Colt Models 645, 645E, and 646 respectively).  

The transitional 700 series had more or less all the configurations developed during the testing of M16A1E1 types.  With A1 or A2 sights, with A1 or A2 lowers, with S-1-F or S-1-3 trigger groups, but all with A2 furniture and most with the case deflector lump (some true A1 uppers were used early on in the production of 700 series guns).  The Canadian firm of Diemaco got the rights to license produce the 715 as the C7.  From my table  the 711s were all S-1-3-F (and I'm not sure about this, my notes suggest this being the case for Turkish contract guns) with lightweight barrels, and early production did not have the case deflector.  In terms of other 700 series 20" rifles, there were (known to me) the 701, 702, 703, 705, 707, and 713.  The 701 was the export model of the 646, while the 702 was the export model of the 645.  The number 703 was applied to a gas piston project, but also an export rifle with an A1 profile barrel and unknown trigger group.  The 705 should have been more or less identical to the 702, which makes me think that there was either some paperwork requirement for a separate model number (separate export contract) or that they assigned a model number when they finally did run out of A1 lowers to build rifles with.  Same applies to the 707, 713 and 719.  I believe someone on these boards actually had a replacement upper from a Dutch contract for 700 series 20" rifles that was marked on the box 7xxH (I believe DC719H), so that might suggest the former reason rather than the latter for these discrepancies.

Mike, I might've been thinking of that book. I believe you were the one who mentioned it in a previous thread. Can you give some details on the one you're building?

From The Black Rifle

How long did you have to wait for one?
Do you just grab one from the pile, or do you save lower or significant  serial numbers for yourself?

Ahhh so you do know how it feels to wait for the RetroGnomes to complete their work.

Wicked. Thanks osprey! Mike, sounds like what I'm doing. I'm going to slap it all together with an A1 barrel until I can find a gov't profile barrel, which could be... well, who knows when.

Two very serious questions: A1 or A2 port door, and round or teardrop FA?

teardrop FA

IM  sent

Homemade mutt gun:

A2 Lower
A2 Bushy Dissapator upper / barrel
A1 Trap Stock
A1 Grip
A2 Guards

Colt 645 from the SAR Colt ID Guide.

Wicked! RMiller, you're the man!

Here's the pics I posted in a past thread from Rock Island Arsenal:

It's labeled "M16A1E2 Final Prototype."
Are the big head FA unusual or did they just appear on early A2s?
I remember seeing several of them at boot-camp in '03.

I'm not sure about the big-head FAs I would assume they were on some of the early A2s and were replacements for some A1s.

Thanks for the pictures guys. I'm going to go with a teardrop FA, but now I have to choose between A1 or A2 port door. The Model 645 RMiller posted has a flat slip ring, so I'll stick with that. I don't have a gov't profile or HBAR, though, so A1 pencil barrel will have to work for now. I'm hoping to get my gray A2 upper in this week!

That's interesting.  I wasn't aware of a M16A1E2.  Perhaps that's what actually became the M16A2.  I wonder what differences besides the forward assist button might have existed between the A1E1 and A1E2.

If the camo'd A2 is one of the first, it appears that it lacked receiver reinforcements, had a flat slip ring, teardrop FA, A1 port door, and A1 grip. I plan to build mine with teardrop FA, NDS-16A1 lower, flat slip ring, A1 grip, and A2 stock. I'm not sure if I want to use an A1 or A2 port door.

IIRC, that's exactly it - mainly a difference in the uppers - rear sight. The barrels were 1:7 by that time, although from what I understand, the early ones were A1 profile, before they went to the A2 profile (.750 under the FSB) Whether or not that is one of the additional differences between the E1 and E2 I don't know - someone far smarter than me (pretty easy to fit into that category ) probably has the info somewhere, but it would sure make sense. Dewatter's 5.56 timeline has some info about this IIRC, and would be worth perusing again.

The way I remember it described to me in ROTC was that they didn't have enough of the A2 upper receivers to go around, so they built or rearsennalled  A1 rifles to new specs (furniture, barrel twist) to take up the slack - so it wasn't really a 'transitional' model as much as a stop-gap measure. I was in ROTC in the mid-80's, whether or not my instructor was full of it or if that was just what he was told, I don't know, but that's always been what I understood about the A1's with A2 furniture. Of course, it's just hearsay evidence, but it makes a certain sort of sense.

D.E. Watter's timeline has the M16A1E1 being standardized as the M16A2.  No mention is made of an M16A1E2.

I went back through my pics and enlarged some key features and descriptions for you guys.  My camera wasn't the greatest, sorry.

Its interesting, as the rifle labeled as the M16A1E2 appears to still have an A1 lower.  The second evaluation M16A1E1 also appears to have had a case deflector, which either fell of or was removed.

After reading this, I going to build a copy of one of the rifles in the middle of the photo. I have all the parts or have them order. The buttstock seems to have a A1 butt plate. The hole drill in the upper receiver at the elevation knob is the only real work to do. Then I guess re-index the numbers on the knob to read out the back instead on the side.

Now the only question is what color to do it in XM-Grey or Black?

Gray!

My A2 upper should be here in the next day or two. Then it's just a matter of putting it all together. Well, crap - I forgot that I don't have a teardrop forward assist on hand.

I guess I'll  have Victor work the magic on the A2 upper. I order a A2 complete upper for the build. Also order the LMT-001K  Adjustment Knob for A1 Rear Sight from Bushmaster. That will replaced the bevel knob that comes on the upper.  Witch one are you building?

Just when I thought it safe to visited this place agian, now another build.

GVS

And so it begins... I posted a WTB ad on the EE about two weeks ago for a gray A2 upper. The only response I got was for a stripped Colt A2, new condition, in "preban gray." I bit, and boy, is she a beauty! And not really preban gray, IMHO.

Damn that looks weird.

Nice but weird.

Looks like a start.
I have a complete colt carbine with a grey A2 upper and LW 16" barrel. I have thought of use it and replaceing it with a NoDak A1 upper.

GVS

I finished mine today, used parts I had on hand. Grey Colt upper on a NDS-16A1 lower. I'll post some pics when I get back in town next weekend.

Now my Colt A2 rifle needs a barrel!  I have one on order to replaced it. I hate robbing Peter to pay Paul.

GVS

I'm not going to bother with getting a government profile barrel just yet. Got too many other irons in the fire. Hopefully in a couple of months I'll be able to find one at a reasonable price, but for now I am just going to assemble the thing with an A1 barrel and rock with that.

I think I would order the barrel today so you will be able to build your rifle by Christmas or so...

Are you going to cut the range setting window?  It can be seen, sort of, in this pic (thanks Scooby).


You'd read what your rear sight was set at the window instead of on the side.

I'm not. I don't have the tools, the skill, or the heart to do it to this beautiful upper. Guess mine will just have to be less correct.

Not trying to poop on anyone's parade, but I think we may have overlooked something...

Shade00 did say experimental...

I must admit that this is the first time I've heard of a M16A1E2 variant.  It does seem odd that it is dated 1981, yet the Aberdeen Technical Feasibility Test which ran from December 1981 to November 1982 used the M16A1E1.  The rifles in these tests had the new furniture (except for the finger groove pistol grip), goverment-profile A2 barrel, 3rd burst, new muzzle compensator, elevation adjustable rear sight with a window in the rear of the carrying handle, square front sight, and a glued-on Brunton Bump.  However, they were still built on M16A1 lowers. The reinforced A2 lower seems to have been inspired by an incident during the cold temperature phase of the testing when the rear of a M16A1's lower fractured and broke off during drop testing.

While growing quite large (nearly 600 pages), my 5.56mm Timeline is by no means complete.  I'm at the mercy of the availability of primary sources and the accuracy of existing secondary sources.  I hesitate to include the M16A1E2 without additional supporting documentary material, lest it is a typo, a misinterpretation on behalf of the curators, or a colloquial designation.

Well here is mine. I finally set up the camera equipment and got some pics. I still might drill the hole on the back of the handle for the elevation wheel.

I hope you have made some progress with your rifle.

GVS

I love seeing prototype pics - very cool! I'm just waiting on one of you guys to either grind off the Brunton bump, or build one up with a TIG to make it look like the earlier version. Weird looking. FWIW, I nearly bought an A2 upper from a member here awhile back that I wanted to use for an early M4 build (I've seen pics of them w/o FAs...) that was a LMG upper, and it had the FA milled off - looked just like a 605 upper, but was A2. I like stuff that's 'different'.

RRA has them with out the bump for the 9MM. Just need to drill the gas tube hole.