WHat is it?

[jaysouth]

http://i1223.photobucket.com/albums/dd507/jaysouth100/SEAL%20modified%20M-16_zps2m0qcho3.jpg (http://s1223.photobucket.com/user/jaysouth100/media/SEAL%20modified%20M-16_zps2m0qcho3.jpg.html)

I wonder if the stock telescopes? The site where I stole this image, suggests that it was an M-16 modified by Navy SEALS for delta warfare in VN.

[Ithaca Gunner]

Looks like an early version of the XM 177 submachinegun.

[Artful]

Yep looks like an early Commando alright
CAR-15
https://bpullignwolnet.dotster.com/retroblackrifle/sitebuilder/images/609-1-600x334.jpg
had some growing under war time conditions...

the one you posted
http://i3.photobucket.com/albums/y86/mossie500/DSCF0033.jpg
http://i3.photobucket.com/albums/y86/mossie500/DSCF0034.jpg

[runfiverun]

and yet they tried it again and again all of them complaining about the rounds effectiveness.
shaking my head.

[Scharfschuetze]

and yet they tried it again and again all of them complaining about the rounds effectiveness.
shaking my head.

I saw and shot the CAR 15 in VN, and was immediately put off by it's ear splitting report. It actually had an extended flash hider which was supposed to reduce the report from the very short barrel. I handed it off and was satisfied to continue on with the the standard weapons of the time.

When we were issued the M4A1 (SOPMOD I), I had a bit of deja vue, but no option not to use it. It's matured into a pretty good platform and it's slightly longer barrel compared to the Commando reduces the report quite a bit and I guess improves the rounds velocity. As I recall, there is about a 200 fps loss in velocity in comparison with the M16 A2 using green tip ammo. There is still the need for a heavier round and thus the birth of the Designated Marksman Rifle (SCAR and M14, both in 7.62 NATO) several years ago. My son uses the SOPMOD II version of the M4A1 and has similar praises as well as criticisms as I do.

[runfiverun]

they don't even have to change the rifle nor the magazines to make the rifles more effective.
the military has upgraded their rifles many times in the past, and at a substantial cost savings.
this is one of those times it actually would be good business to make the change.
there are a number of rounds that could be used and all that would be necessary would be a barrel change.
the ammunition changeover would be pretty painless too right on down to the copper discs ordered to make the cases from.

[Artful]

Well with a list of AR15 hosted cartridges like...


.17 Remington (https://en.wikipedia.org/wiki/.17_Remington)
.17x223
.204 Ruger (https://en.wikipedia.org/wiki/.204_Ruger)
.223 Remington (https://en.wikipedia.org/wiki/.223_Remington) - .223 cartridges may function in a 5.56×45mm rifle, however 5.56×45mm cartridges will produce excessive pressure in a .223 rifle.
.243 Winchester Super Short Magnum (https://en.wikipedia.org/wiki/.243_Winchester_Super_Short_Magnum)
.25 Winchester Super Short Magnum (https://en.wikipedia.org/wiki/.25_Winchester_Super_Short_Magnum)
.277 Wolverine] (6.8x39)
.30 Carbine (https://en.wikipedia.org/wiki/.30_Carbine)
.30 Remington AR (https://en.wikipedia.org/wiki/.30_Remington_AR)
300 AAC Blackout (7.62×35mm) (https://en.wikipedia.org/wiki/300_AAC_Blackout_(7.62%C3%9735mm))
7.62x40WT
.300 Whisper (https://en.wikipedia.org/wiki/.300_Whisper)
.375 Reaper (https://en.wikipedia.org/w/index.php?title=.375_Reaper&action=edit&redlink=1)
.40 S&W (https://en.wikipedia.org/wiki/.40_S%26W)
.45 ACP (https://en.wikipedia.org/wiki/.45_ACP)
.450 Bushmaster (https://en.wikipedia.org/wiki/.450_Bushmaster)
.458 SOCOM (https://en.wikipedia.org/wiki/.458_SOCOM)
.50 Beowulf (https://en.wikipedia.org/wiki/.50_Beowulf)
.50 Action Express (https://en.wikipedia.org/wiki/.50_Action_Express)

Centerfire calibers metric measurement[edit (https://en.wikipedia.org/w/index.php?title=List_of_AR_platform_calibers&action=edit&section=4)]

5.45×39mm (https://en.wikipedia.org/wiki/5.45%C3%9739mm)
5.7×28mm FN (https://en.wikipedia.org/w/index.php?title=5.7%C3%9728mm_FN&action=edit&redlink=1)
6.5mm Grendel (https://en.wikipedia.org/wiki/6.5mm_Grendel)
6.5mm Patriot Combat Cartridge (https://en.wikipedia.org/w/index.php?title=6.5mm_Patriot_Combat_Cartridge&action=edit&redlink=1)
6.8mm Remington SPC (https://en.wikipedia.org/wiki/6.8mm_Remington_SPC)
7.62×37mm Musang (https://en.wikipedia.org/wiki/7.62%C3%9737mm_Musang)
7.62×39mm (https://en.wikipedia.org/wiki/7.62%C3%9739mm)
7.62×40mm Wilson Tactical (https://en.wikipedia.org/wiki/7.62%C3%9740mm_Wilson_Tactical)


Frankly we still seem to be chasing performance like the .280 British promised in 1951.
https://upload.wikimedia.org/wikipedia/commons/4/41/280british.jpg
Various .280 Ball Cartridges. Orange cased cartridge is made out of aluminium.
https://en.wikipedia.org/wiki/.280_British
Recoil of the .280 British cartridge was calculated to be a little under half of the .303 British. Long range performance actually surpassed that of the .303 British, and shooters reported that it was much more comfortable to fire with the reduced recoil and reduced blast.

Bullet weight/type___ Velocity___________Energy
139 gr (9 g) Ball____ 2,545 ft/s (776 m/s) 1,980 ft·lbf (2,680 J)

140 gr (9 g) Ball
7 mm Mk 1Z_______2,549 ft/s (777 m/s) 2,004 ft·lbf (2,717 J)

[BattleRife]

http://i1223.photobucket.com/albums/dd507/jaysouth100/SEAL%20modified%20M-16_zps2m0qcho3.jpg (http://s1223.photobucket.com/user/jaysouth100/media/SEAL%20modified%20M-16_zps2m0qcho3.jpg.html)

I wonder if the stock telescopes? The site where I stole this image, suggests that it was an M-16 modified by Navy SEALS for delta warfare in VN.

It's a Colt M607 carbine, or far more likely, a recently assembled reproduction of a Colt M607. The M607 was Colt's second attempt at making a carbine version of the AR-15, and the first to feature a collapsible stock. They apparently were all marked "Property of US Government / GX-5857". I don't know how many Colt built, I would guess a couple of hundred max, but there has been an explosion of interest in them by the Retro AR crowd and something of a cottage industry in recreating them.

[Scharfschuetze]

For a good history on the M16 and its derivatives to about 1990 or so is the book titled: "The Black Rifle"

Link: http://www.amazon.com/Black-Rifle-Retrospective-Modern-Military/dp/0889351155/ref=sr_1_1?s=books&ie=UTF8&qid=1441469304&sr=1-1&keywords=the+black+rifle+book

The Army never really wanted to go to a smaller calibre rifle and was fully satisfied with the M14. The politics of the 60s under the Kennedy administration and the onset of the Vietnam war all conspired to give us the M16/Car 15/M4 series of weapons, for better or for worse. Somehow a rifle meant to be an Air Force air crewman's weapon or Air Force security force rifle became the main battle rifle for the USMC and the US Army.

Here's the guy who was probably most responsible for the decision to adopt the 5.56 and the M16 rifle. Robert McNamara, the secretary of defense under President Kennedy. He was a Ford executive prior to becoming SECDEF and he brought that corporate style of thinking to the Department of Defense.

[goodolejim]

You didn't mention his middle name is Strange. Robert Strange McNamara, and yes he was strange!