Anyone doing "retro" M4's yet?

[Circle_10]

I seem to recall reading that the 7xx-series carbines produced toward the end of their run had full on "M4" feedramps.
Prior to that, they had the "extended carbine" ramps.
However I wonder if the earliest 723s and 733s, back from like the early/mid 80s, had extended ramps at all.

I do love a good 7xx-series carbine discussion. My absolute favorite Retro ARs, what with me having grown up in the 80s and 90s.

Just for the hell of it, here's this:

Apparently an XM4/RO720 with one of the barrel profile options that was not selected.

To be honest, I'm not clear what the rationale behind this profile even was. At least with the familiar M4 stepped profile you understand that it was an A2/government profile barrel, but stepped to facilitate mounting of the M203.
With the profile pictured, I really don't know what they would have been going for.

[ABNAK]

I seem to recall reading that the 7xx-series carbines produced toward the end of their run had full on "M4" feedramps.
Prior to that, they had the "extended carbine" ramps.
However I wonder if the earliest 723s and 733s, back from like the early/mid 80s, had extended ramps at all.

I do love a good 7xx-series carbine discussion. My absolute favorite Retro ARs, what with me having grown up in the 80s and 90s.

Just for the hell of it, here's this:

Apparently an XM4/RO720 with one of the barrel profile options that was not selected.

To be honest, I'm not clear what the rationale behind this profile even was. At least with the familiar M4 stepped profile you understand that it was an A2/government profile barrel, but stepped to facilitate mounting of the M203.
With the profile pictured, I really don't know what they would have been going for.

OMG! Taking the retardation of the A2/Government profile a step further?

[RetroRevolver77]

I seem to recall reading that the 7xx-series carbines produced toward the end of their run had full on "M4" feedramps.
Prior to that, they had the "extended carbine" ramps.
However I wonder if the earliest 723s and 733s, back from like the early/mid 80s, had extended ramps at all.

I do love a good 7xx-series carbine discussion. My absolute favorite Retro ARs, what with me having grown up in the 80s and 90s.

Just for the hell of it, here's this:

Apparently an XM4/RO720 with one of the barrel profile options that was not selected.

To be honest, I'm not clear what the rationale behind this profile even was. At least with the familiar M4 stepped profile you understand that it was an A2/government profile barrel, but stepped to facilitate mounting of the M203.
With the profile pictured, I really don't know what they would have been going for.

Same thing, it's just stepped under the front sight rather than halfway down the barrel.

[Circle_10]

Same thing, it's just stepped under the front sight rather than halfway down the barrel.

Why not just have a fully lightweight profile barrel than? A2/government profile is light under the handguard, then .750 at the FSB. That's why this profile above makes even less sense to me. Why have it heavier just for the last couple inches. It even looks like it's .625 at the FSB like the early 723s.

The other candidate profile was, IIRC, a 14.5 pencil barrel, but .750 at the FSB. Basically what the Canadians used on the original C8 carbines.

[Gator Monroe]

74A25498-8D32-4C2D-BBBB-0319C6E45C05.jpg Dedicated 22 M4gery

[Gator Monroe]

1C2CFF34-2DFF-47EF-8FF4-1C6E7F201B47.jpg Bottom is A2 Upper CAR 15 style build

[SteyrAUG]

Nah, the version issued in 94 flat top and N1 stocked.

So how is that different from a 2004 vintage 6920?

[Hammered_Pair]

So how is that different from a 2004 vintage 6920?

The 16 in barrel I suppose is the difference. I know the retro crowd is crazy on details.

[Circle_10]

The 16 in barrel I suppose is the difference. I know the retro crowd is crazy on details.

As clone projects go, It's a pretty simple one. Get a 6920 lower and stick a 14.5" 6921 upper on it (either SBR the lower or P/W an extended A2 on the barrel), and add detachable carry handle and an N1.
Or you could do pretty much the same thing without even bothering to go all Colt too. Depends how close one wants to get.

[Renegade04]

As clone projects go, It's a pretty simple one. Get a 6920 lower and stick a 14.5" 6921 upper on it (either SBR the lower or P/W an extended A2 on the barrel), and add detachable carry handle and an N1.
Or you could do pretty much the same thing without even bothering to go all Colt too. Depends how close one wants to get.

Although not a retro, this is a simple M4 clone I did a couple years ago. It sits on a Colt M4 Carbine lower with a M&A parts CAR stock. The barrel is a 14.5" Colt with a P&W extended A2 FH.