The cheaper used/exc M16A1 upper, with 3 prong brake.

No mfg. or forge codes.  "12" on underside of barrel. Forward assist.  Split lock washer behind brake.  

I think this is an XM16E1 upper or an M16A1 upper with a pre-1967, pre chrome lined barrel. (CDNN advertised these as chrome lined).

Condition externally was near new - handguards rattley laterally after I removed and replaced - is there a fix for this?

What do you all think?





Note the divot pivot pin area ;)

you might want to clean the muzzle and remove all the fouling, it'll make it easier to tell if the barrel is fully chromelined or not.

Also it's not a 3 prong brake, that's a 3 prong FLASH SUPPRESSOR.  they're two different things for different purposes.

Also I could be wrong but the front sight block appears to be cast instead of  forged, if that's the case someone have replaced the original FSB at one point in time.

The barrel should be date coded.

Quoted: The barrel should be date coded.

Look under the handguard or just in front of the front sight base

I do know that it's a suppressor, but y'all should be glad I even typed brake at 1 am when I posted ;)

No date code on the chamber or in front of the FSB or even BEHIND the FSB under the handguards.

BT

Any way to tell from the muzzle if that's chrome lining? Am used to FAL barrels and AK barrels where it is obvious.

Any tips or tricks for stopping the handguard rattle?

Ah, that is a Colt's XM16E1 upper.  The cast FSB and the missing magnaflux marking is a dead give away for the first year of production, 1964.  No chrome in bore or chamber, no date on barrel.  Details on FSB's, barrel markings and such here:

www.ar15.com/forums/topic.html?b=3&f=118&t=241681

I never seen anything like that still in inventory, don't know how it survived without being updated.  It has to be refinished though, looks like the receiver is painted black?

Wanna sell it?  Probably not, I am calling CDNN..............

Wow, talk about old school.  

I think CDNN's surplus uppers are a great deal, though I prefer the newer A2 variety.

I just called CDNN, thier number is 800-588-9500.  They had 18 more of the ones OODA_Loop bought:

USED, Very Good to Excellent Condition • A1 Upper Assembly • 3-Prong Brake • NO Bolt or Charging Handle • Teardrop Forward Assist • Triangular Handguards • SP1 Sights • Sling Swivel • Bayonet Lug • Flash Hider • 20" Chrome Lined Barrel • Miscellaneous MFG

$269.99

COLUGI

I ordered three.  These are all going to be refurbs, don't see the odds being good that an issue XM16E1 could survive some 40 years in original condition, other then museums or ones left behind in Vietnam.

They also have these, but don't know what they are, but sounds like the same thing that has been going around on gunbroker for $305 (but those come with bolt group and charging handle):

USED, Very Good to Excellent Condition • A1 Upper Assembly • Early Model • NO Bolt or Charging Handle • Teardrop Forward Assist • Triangular Handguards • SP1 Sights • Sling Swivel • Bayonet Lug • Flash Hider • 20" Chrome Lined Barrel • GI Miscellaneous MFG.

$299.99

COLUE

Should have them Friday afternoon, will advise what I get.

Tagged

tagged

Tag

I smell a truck gun.

Seydou

I like it, although I am not really a serious collector; a representative "A1 type" is what I was after rather than each variant.

My boss, a VN Vet, saw it at lunch in my trunk, and may buy it (has to clear with Bank of Wife first).  

"Brings back memories," he said. Does not like the 3-prong, which is fine; I want it.

BT

Does it have M4 feed ramps?

Quoted: The cheaper used/exc M16A1 upper, with 3 prong brake. No mfg. or forge codes.  "12" on underside of barrel. Forward assist.  Split lock washer behind brake.   I think this is an XM16E1 upper or an M16A1 upper with a pre-1967, pre chrome lined barrel. (CDNN advertised these as chrome lined). Condition externally was near new - handguards rattley laterally after I removed and replaced - is there a fix for this? What do you all think? img.photobucket.com/albums/v142/kornjaca/AR15/107_0788.jpg img.photobucket.com/albums/v142/kornjaca/AR15/107_0787.jpg img.photobucket.com/albums/v142/kornjaca/AR15/107_0795.jpg Note the divot pivot pin area ;) img.photobucket.com/albums/v142/kornjaca/AR15/107_0797.jpg img.photobucket.com/albums/v142/kornjaca/AR15/107_0798.jpg img.photobucket.com/albums/v142/kornjaca/AR15/108_0806.jpg img.photobucket.com/albums/v142/kornjaca/AR15/108_0815.jpg img.photobucket.com/albums/v142/kornjaca/AR15/108_0819.jpgimg.photobucket.com/albums/v142/kornjaca/AR15/108_0823.jpg

Could you take a better pic of each side of the receiver only, so we can tell if it has been refinished for sure?

Quoted: Could you take a better pic of each side of the receiver only, so we can tell if it has been refinished for sure?

Gladly. Oh, I want to thank Ekie for earlier posting pics of his research, it helped me with my initial assessment here.  I suspect it has been refinished with whatever the spec spray is for when the finish is 50% bare metal (I cannot find my TM's and don't really need to look it up online right now. You know what I mean ;)


Looks like external pitting on the barrel, light, covered. Hard to tell. Flash is on and everything looks gray - it is really quite black.

CDNN top center with two Colts - a vintage M16A1 and a 1980s large-hole C7 (note the early pattern A2 forward assist with cutout on the receiver side - my 6520 upper has a smaller unit).  Also note the CDNN unit's port door.
Finish is smooth and black, but there is some CLP and/or Synthetic gun oil visible, you know the drill:


Inside!~

Just got mine.  All three appear to have all orignial parts other then possibly the handguards, will inspect them tonight.  All have three prong flash hiders, no forge code with forward assist, counter bored pivot pin hole, A1 port door cover, front swivels held on by roll pin, and first style purdy forged FSB.  Unfortunately none of them had the early cast FSB like OODA_Loop got.  Upper receivers are painted black and tow have the Colt's arsenal codes stamped in front of the port dor.

Two are circa 64-67 with the 12 marking near the muzzle on the barrel.  Both have bare steel swivels.  Tapped hole for front sight base does not go through.  One is totally refinished, steel parts are heavily blasted and parked, aluminum parts painted.  The proof marks near the FSB are gone, rusted and or blasted off.  The other one has the orignial rusty and worn finish on the steel parts, and the receiver slip ring area was painted over while assembled with the closed port door.  On this one no paint was applied to the underside/inside of the receiver.

The other upper is M16A1 upper circa 1967/68.  Appears to be Hydramatic or H&R, no Colt's arsenal codes, and the forging is shapped differently.  It has a chrome chamber with a C marking near the muzzle on the barrel, and a run together MP proof stamp by the FSB.  Tapped hole for front sight post goes all the way through.  I have pictures of this variation of the barrel markings, have not gotten around to posting them in the guide though.  Swivel is plastic coated.  Orignial rusty and worn finish on the steel parts, and the receiver slip ring area was painted over while assembled with the closed port door.

Will strip them down, clean them up a bit, and part out the parts I don't want.

I actually really like this, but want a chrome-lined chamber and bore. The upper is really nicely machined and I want to keep the three-prong flash suppressor and washer; I may swap out or sell the barrel.

Damn these AR's! They are addictive!

Quoted: Note the divot pivot pin area ;) img.photobucket.com/albums/v142/kornjaca/AR15/107_0797.jpg

Is there a large-to-small pin adaptor in there??

Quoted: Quoted: Note the divot pivot pin area ;) img.photobucket.com/albums/v142/kornjaca/AR15/107_0797.jpg Is there a large-to-small pin adaptor in there??

Nope! Scroll up to Ekie's review of the ones he got from CDNN. The pivot pin hole is slightly rebated, but it is an otherwise 'standard' milspec .250 pin hole. I don't know anything else except that it is an early feature. Ekie?

The counter bore was used on the original AR-15.  I don't have an original front pin, so will have to describe this without the benefit of a picture.  These original Air Force AR-15 rifles were slab sides and used a push pin with a detent about 3/4 of the way down the pin. The pin and hole  were both about .250" except were the upper is counter bored to a larger diameter on the left side.  The pin goes in from the right and once it gets to the counter bored area of the upper receiver the detent pops out holding the pin in place.  This set up allows the pin to be about flush on the left side. The pivot pin can also be inserted from left to right, but because the right side of the upper lacks the counter bore the detent will not pop up and engage anything to keep it in place.  Same story if you use a later upper with no counter bore on a early AR-15, the pin will insert either way, but the detent will not engage to hold it in place.  Eventually Colt's dropped this ArmaLite design and came up with a captive pin.  This modern captive pin design that we are familiar with does not require the counter bored upper receiver pivot pin hole.  Colt' continued to counter bore their pivot pins holes in their M16/M16A1/etc for several years, so that these later uppers were still compatible with the "slab side" lower, or type A lower if you will.

This all Greek?  Once I find one of these early pivot pins I will include it in the guide with pics, and am sure it will make sense.

.

Quoted: The counter bore was used on the original AR-15.  I don't have an original front pin, so will have to describe this without the benefit of a picture.  These original Air Force AR-15 rifles were slab sides and used a push pin with a detent about 3/4 of the way down the pin. The pin and hole  were both about .250" except were the upper is counter bored to a larger diameter on the left side.  The pin goes in from the right and once it gets to the counter bored area of the upper receiver the detent pops out holding the pin in place.  This set up allows the pin to be about flush on the left side. The pivot pin can also be inserted from left to right, but because the right side of the upper lacks the counter bore the detent will not pop up and engage anything to keep it in place.  Same story if you use a later upper with no counter bore on a early AR-15, the pin will insert either way, but the detent will not engage to hold it in place.  Eventually Colt's dropped this ArmaLite design and came up with a captive pin.  This modern captive pin design that we are familiar with does not require the counter bored upper receiver pivot pin hole.  Colt' continued to counter bore their pivot pins holes in their M16/M16A1/etc for several years, so that these later uppers were still compatible with the "slab side" lower, or type A lower if you will. This all Greek?  Once I find one of these early pivot pins I will include it in the guide with pics, and am sure it will make sense.

Mike

I would suspect Colt counterbored some front pivot holes for AF M16A2 conversion kits because I had a M6601 that had a counterbored hole.

Quoted: The counter bore was used on the original AR-15.  I don't have an original front pin, so will have to describe this without the benefit of a picture.  These original Air Force AR-15 rifles were slab sides and used a push pin with a detent about 3/4 of the way down the pin. The pin and hole  were both about .250" except were the upper is counter bored to a larger diameter on the left side.  The pin goes in from the right and once it gets to the counter bored area of the upper receiver the detent pops out holding the pin in place.  This set up allows the pin to be about flush on the left side. The pivot pin can also be inserted from left to right, but because the right side of the upper lacks the counter bore the detent will not pop up and engage anything to keep it in place.  Same story if you use a later upper with no counter bore on a early AR-15, the pin will insert either way, but the detent will not engage to hold it in place.  Eventually Colt's dropped this ArmaLite design and came up with a captive pin.  This modern captive pin design that we are familiar with does not require the counter bored upper receiver pivot pin hole.  Colt' continued to counter bore their pivot pins holes in their M16/M16A1/etc for several years, so that these later uppers were still compatible with the "slab side" lower, or type A lower if you will. This all Greek?  Once I find one of these early pivot pins I will include it in the guide with pics, and am sure it will make sense.

Alright, I think I got ya...Thanks Ekie!

Quoted: I would suspect Colt counterbored some front pivot holes for AF M16A2 conversion kits because I had a M6601 that had a counterbored hole.

I have wondered about that. There is also a problem with quite a few Air Force rifles with no forward assist cuts in the carriers, and the conversion kit does not include a carrier.

My CDNN upper came with an M16A1 flash suppressor and chrome lined barrel.  I guess I have a later issued upper.

These uppers were disgusting filthy.  Spent all my free time this weekend cleaning them up.  Worked on the bores last night and two of them are pitted.  Going to send all three back for a refund.  Would do an exchange, but looks like the odds are these are mostly toast.  Would not recommend these, unless you really need a no forge code upper receiver for a XM16E1 or XM177 type project.  For shooters I recommend the nice complete refurb uppers that are going around now.

Ekie, I think I need a chrome bore - pm or email  me if you're interested in the unit above, I may be willing to part with it - am torn, as it's nifty and retro, but...

Are the 3-prongs hard to find? I like it.

I also like the port door ;)