M4A1 project (pics) > AR Discussions

Posted: 4/10/2005 12:20:15 PM EDT

[#1]

Quoted:
me like but...HOW CAN IT BE AN A1 IF IT DOESNT HAVE A HANDLE? is it just the barrel?? im confused...

Quoted:
The M4A1 is full auto as opposed to three round burst. There were problems with the light barrel and full auto, so they ended up having heavy barrels. This upper has the heavy barrel. Colt's referred to the full auto heavy barrel M4A1 as the RO921HB (like is says on the box).

Posted: 4/10/2005 12:31:51 PM EDT

[#2]

Quoted:
Just to toss in $.02 worth of history- One reason you may have that storied barrel in your possession is that the ~3000 RO921HB uppers sent to the Army in 2001 were eventually all tossed and replaced around 2003 by new ones. Apparently there was some defect in the original construction.. I've heard different stories about the exact nature of the flaw- one story was just that many barrel nuts were not torqued properly- the other story was an actual design flaw in the barrel. Maybe KMFDM or some Colt RKI can step in with more info.

FWIW, I know of RO921HB uppers from that time that run flawlessly- the problems may have only been in a small (but unacceptably large) % of the total run..

HTH

I have seen quite a few misassembled M4 uppers myself. Even started a thread on the topic here:

www.10-8forums.com/ubbthreads/showflat.php?Cat=0&Number=2660&an=0&page=0#2660

Every time I bring up the problems with Colt's and their sloppy assembly of their carbines, I get little response, and not much in the way of answers.

In addition this particular upper did not function in the condition I got it in (no doubt the reason it had not been shot much). Unlike the A1 and A2, with M4 uppers am careful to test them full auto (on my buddies registered lower) prior to spending any amount of time or money on them. Any how, got this one up and running, and run it does, like a sewing machine.

In regards to the 2001 issue M4A1's, have not heard of those being replaced. I know a guy in 10th SFG, and last I knew they still were using their 2001 issue M4A1's, and still had some from the first issue (1995/96). That being said, don't know a soul in 3rd SFG, but apparently they dumped some huh?

Posted: 4/10/2005 12:34:10 PM EDT

[#3]

Thanks for the thread. I learned a lot. At first I thought I was just looking at another AR. It sucks being a newbie to ARs cause I cannot recognize all of the details of each weapon.

Posted: 4/10/2005 1:49:47 PM EDT

[#4]

Quoted:
Quoted:
me like but...HOW CAN IT BE AN A1 IF IT DOESNT HAVE A HANDLE? is it just the barrel?? im confused...

Quoted:
The M4A1 is full auto as opposed to three round burst. There were problems with the light barrel and full auto, so they ended up having heavy barrels. This upper has the heavy barrel. Colt's referred to the full auto heavy barrel M4A1 as the RO921HB (like is says on the box).

To expand on what Ekie said, the military M4 was 3-shot burst. When they went to full-auto instead, it was designated the M4A1.

BTW, my M4A1 barrel is dated 04/04.

Posted: 4/12/2005 8:09:26 AM EDT

[#5]

Quoted:
Thanks for the thread. I learned a lot. At first I thought I was just looking at another AR. It sucks being a newbie to ARs cause I cannot recognize all of the details of each weapon.

Got a similar thread here detailing a earlier M4gery project:

ar15.com/forums/topic.html?b=3&f=118&t=231110

Posted: 4/12/2005 10:00:45 AM EDT

[#6]

Quoted:

To expand on what Ekie said, the military M4 was 3-shot burst. When they went to full-auto instead, it was designated the M4A1.

I am not sure what you are trying to say but that is not entirely correct.

The M4 is still the standard carbine for the US military. It is 3 shot burst

The M4A1 is SOCOM only.

Posted: 4/12/2005 10:41:56 AM EDT

[#7]

Quoted:
Quoted:

To expand on what Ekie said, the military M4 was 3-shot burst. When they went to full-auto instead, it was designated the M4A1.

I am not sure what you are trying to say but that is not entirely correct.

The M4 is still the standard carbine for the US military. It is 3 shot burst

The M4A1 is SOCOM only.

Both the M4 and M4A1 have been adopted as Standard A, and both are in production. The vast majority of M4A1's are going to SOCOM, but the Big Army does get a few. In addition, all M4A1's delivered for SOCOM since 2003 come with the heavy barrel, prior to that it was optional (of course, other buyers can get other options from Colt's).

Posted: 4/12/2005 3:29:49 PM EDT

[#8]

Quoted:
Quoted:
Quoted:

To expand on what Ekie said, the military M4 was 3-shot burst. When they went to full-auto instead, it was designated the M4A1.

I am not sure what you are trying to say but that is not entirely correct.

The M4 is still the standard carbine for the US military. It is 3 shot burst

The M4A1 is SOCOM only.

Both the M4 and M4A1 have been adopted as Standard A, and both are in production. The vast majority of M4A1's are going to SOCOM, but the Big Army does get a few. In addition, all M4A1's delivered for SOCOM since 2003 come with the heavy barrel, prior to that it was optional (of course, other buyers can get other options from Colt's).

Yes both are in production and both are standard. But the M4 is standard carbine for the entire military. Army units that have the M4A1 are attached to SOCOM.

Just like the M1 carbine was standard for the military and the M1A1 was standard for the elite (paratroopers).

This is the same as the Knight's RAS and RIS. The RIS is standard for SOCOM, however, some army units in SOCOM have a RAS because they are sort of inbetween SOCOM and the rest of the military.

Posted: 4/13/2005 2:53:48 AM EDT

[#9]

Quoted:
This is the same as the Knight's RAS and RIS. The RIS is standard for SOCOM, however, some army units in SOCOM have a RAS because they are sort of inbetween SOCOM and the rest of the military.

i'm not sure this is an entirely accurate assumption. i know my old unit ,which was JSOC/SOCOM initially had RIS units and thenDXed them for the RAS because it was more stable for mounting optics and just generally more durable. Units have their own "allowance" and will buy what they think is best for the missions they conduct -- this is especially true of the high budget SOCOM units.

Posted: 4/13/2005 4:08:09 AM EDT

[#10]

Ekie,

Reference the four marks on the barrel, if they came from an aluminium barrel block they are very easy to remove. Scrub the marks with a brass brush (old bore brush will work) saturated with Hoppe's #9. The aluminum will come right off and not harm the finish below. HTH

Larry

PS - Lets see some pics of the "new" (old) parts on your 601.

Posted: 4/13/2005 5:23:04 AM EDT

[#11]

Quoted:
Ekie,

Reference the four marks on the barrel, if they came from an aluminium barrel block they are very easy to remove. Scrub the marks with a brass brush (old bore brush will work) saturated with Hoppe's #9. The aluminum will come right off and not harm the finish below. HTH

Larry

PS - Lets see some pics of the "new" (old) parts on your 601.

I tried Barnes X, with no luck. Don't think I want to take a wire brush to it though.

Posted: 4/13/2005 5:26:23 AM EDT

[#12]

Quoted:
Quoted:
Quoted:
Quoted:

To expand on what Ekie said, the military M4 was 3-shot burst. When they went to full-auto instead, it was designated the M4A1.

I am not sure what you are trying to say but that is not entirely correct.

The M4 is still the standard carbine for the US military. It is 3 shot burst

The M4A1 is SOCOM only.

Both the M4 and M4A1 have been adopted as Standard A, and both are in production. The vast majority of M4A1's are going to SOCOM, but the Big Army does get a few. In addition, all M4A1's delivered for SOCOM since 2003 come with the heavy barrel, prior to that it was optional (of course, other buyers can get other options from Colt's).

Yes both are in production and both are standard. But the M4 is standard carbine for the entire military. Army units that have the M4A1 are attached to SOCOM.

Just like the M1 carbine was standard for the military and the M1A1 was standard for the elite (paratroopers).

This is the same as the Knight's RAS and RIS. The RIS is standard for SOCOM, however, some army units in SOCOM have a RAS because they are sort of inbetween SOCOM and the rest of the military.

Did get a chance to look up the heavy barrel on the M4A1 last night. The SOCOM M4A1 use to come with an optional heavy barrel, then effective 2003 the heavy barrel was standard, and the standard barrel is now optional.

When I get a chance I will dig around for more info on the Big Army and the M4A1.

Edit:

Above info on the heavy barrels comes from BRII, according to The Gun Zone all DOD purchased M4A1 carbines come with a heavy barrel, effective 2003:

www.thegunzone.com/556dw-5.html

Posted: 4/13/2005 10:18:44 AM EDT

[#13]

Quoted:
i'm not sure this is an entirely accurate assumption. i know my old unit ,which was JSOC/SOCOM initially had RIS units and thenDXed them for the RAS because it was more stable for mounting optics and just generally more durable.

That's funny, in that I all ready DXed the RIS for a RAS. It will also end up with a Comp M2 rather then the CompM/XD.

Posted: 4/13/2005 3:20:29 PM EDT

[#14]

Quoted:
Quoted:
i'm not sure this is an entirely accurate assumption. i know my old unit ,which was JSOC/SOCOM initially had RIS units and thenDXed them for the RAS because it was more stable for mounting optics and just generally more durable.

That's funny, in that I all ready DXed the RIS for a RAS. It will also end up with a Comp M2 rather then the CompM/XD.

The RIS is still standard for SOCOM. This is straight from codeblue at KAC. He told me this a few months ago.

Scott

Posted: 4/13/2005 4:14:12 PM EDT

[#15]

Quoted:
Quoted:
Quoted:
i'm not sure this is an entirely accurate assumption. i know my old unit ,which was JSOC/SOCOM initially had RIS units and thenDXed them for the RAS because it was more stable for mounting optics and just generally more durable.

That's funny, in that I all ready DXed the RIS for a RAS. It will also end up with a Comp M2 rather then the CompM/XD.

The RIS is still standard for SOCOM. This is straight from codeblue at KAC. He told me this a few months ago.

Scott

Yep, sure enough, I doubt KAC would still make the RIS if not for SOCOM still using them. A strange thing, being that the RAS is WAY better.

Posted: 4/13/2005 4:57:09 PM EDT

[#16]

what do i know -- i was just there.

oh yeah -- and the guy attached to 5th SFG i talked to this morning that verified that they had the RAS and no longer used the RIS -- you don't know what you're talking about either. turn your weapon in and tell the armorer you got the wrong rail system on there --

Posted: 4/13/2005 5:03:44 PM EDT

[#17]

Quoted:
what do i know -- i was just there.

oh yeah -- and the guy attached to 5th SFG i talked to this morning that verified that they had the RAS and no longer used the RIS -- you don't know what you're talking about either. turn your weapon in and tell the armorer you got the wrong rail system on there --

I see it kinda like that weird Trijicon dot sight that is part of the SOPMOD package, next to nobody uses those, instead Aimpoints are used (as far as dot sights go).

Anyhow, agreed that the RIS I had on there was more authentic, but the RAS is WAY better, and as K1196A point out it is also in use.

Posted: 4/13/2005 6:33:05 PM EDT

[#18]

Quoted:
Quoted:
what do i know -- i was just there.

oh yeah -- and the guy attached to 5th SFG i talked to this morning that verified that they had the RAS and no longer used the RIS -- you don't know what you're talking about either. turn your weapon in and tell the armorer you got the wrong rail system on there --

I see it kinda like that weird Trijicon dot sight that is part of the SOPMOD package, next to nobody uses those, instead Aimpoints are used (as far as dot sights go).

Anyhow, agreed that the RIS I had on there was more authentic, but the RAS is WAY better, and as K1196A point out it is also in use.

Yes, the RIS is more authentic for a SOPMOD carbine

Yes, the RAS is better than the RIS

Yes, some SOCOM units use the RAS

Posted: 4/13/2005 6:35:10 PM EDT

[#19]

If you want to build the SOPMOD carbine as it appears in the poster.

You need a RIS and a TA01NSN ACOG.

If you want to build a SOPMOD carbine after it has been in the field, you could use a RIS or RAS and a TA01NSN or Aimpoint

Posted: 4/13/2005 6:54:56 PM EDT

[#20]

Those scratches on that barrel may have come from the ring on a bayonet when it was put on or taken off.

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