CMMG lightweight upper

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[ARCHIVED THREAD] - CMMG lightweight upper

Posted: 2/10/2006 7:33:28 AM EDT

Does anyone know the weight or profile of the 16" CMMG lightweight barrel? I am wondering if it is lighter than the M4 proile because I have heard it is not true lightweight spec...

I have tried to call them but they must be on their way to Shot, so it was a no go.

Any info would be appreciated.

Thanks

Posted: 2/10/2006 7:35:35 AM EDT

[#1]

It is lighter as it's contoured in front and behind the FSB. It's not a lot of weight savings, but it's a few ounces...

Posted: 2/10/2006 8:03:58 AM EDT

[#2]

Contoured to what, do you know?

Posted: 2/10/2006 8:09:47 AM EDT

[#3]

Quoted:
Does anyone know the weight or profile of the 16" CMMG lightweight barrel? I am wondering if it is lighter than the M4 proile because I have heard it is not true lightweight spec...

I have tried to call them but they must be on their way to Shot, so it was a no go.

Any info would be appreciated.

Thanks

Not trying to be a smart @%%, but I didn't know there was a lightweight spec. I thought it was a civilian market creation.

Doc

Posted: 2/10/2006 8:17:11 AM EDT

[#4]

Quoted:
Quoted:
Does anyone know the weight or profile of the 16" CMMG lightweight barrel? I am wondering if it is lighter than the M4 proile because I have heard it is not true lightweight spec...

I have tried to call them but they must be on their way to Shot, so it was a no go.

Any info would be appreciated.

Thanks

Not trying to be a smart @%%, but I didn't know there was a lightweight spec. I thought it was a civilian market creation.

Doc

Well, pencil profile, A1 profile etc...original Colt A1 spec. The .625 or whatever.

Posted: 2/10/2006 11:35:38 AM EDT

[#5]

Quoted:
Not trying to be a smart @%%, but I didn't know there was a lightweight spec. I thought it was a civilian market creation.

Doc

It's the barrel profile the military used for 20+ years before the A2/M4 barrels were released which thickened the barrels from the FSB forward.

Cheebacca, IIRC the CMMG barrels are 0.625 EXCEPT for the area under the FSB which is 0.75". It would make the barrel an ounce or less heavier than a true LW profile.

Posted: 2/10/2006 11:38:46 AM EDT

[#6]

The market has been asking for true 14.5" and 16.5" A1 profile barrels with 1:7 rifling for over a year. They have yet to be produced.

Posted: 2/10/2006 11:40:26 AM EDT

[#7]

the cmmg bbls are .750 turned down to lw profile.

jt distributing shows a 14.5 true lw bbl. in their catolog for some time now.

Posted: 2/10/2006 11:49:32 AM EDT

[#8]

Quoted:
the cmmg bbls are .750 turned down to lw profile.

jt distributing shows a 14.5 true lw bbl. in their catolog for some time now.

So you are saying the same as Forest then, meaning it is lw except under the FSB?

Posted: 2/10/2006 12:05:28 PM EDT

[#9]

The CMMG barrels are light under the handguards and in front of the FSB (.625, superlight, whatever you want to call it), but under the FSB it is normal (.750). Bushmaster makes a true superlight (.625 FSB) as does Eagle Firearms and probably others.

Posted: 2/10/2006 12:23:40 PM EDT

[#10]

So does the BM LW use a different FSB ??

Posted: 2/10/2006 12:37:56 PM EDT

[#11]

Quoted:
So does the BM LW use a different FSB ??

Yes.

Posted: 2/10/2006 1:13:36 PM EDT

[#12]

I suppose the .750 barrel became “standard” when the Marine Corps adopted the Government profile barrel.

The problem is that there aren’t many .625 gas blocks or front sights out there. It would be easy to have barrels turned down to the proper .625 diameter but the other hardware just isn’t readily available.

And that’s a shame because the AR-15 is supposed to be a light rifle. I’ll grant that there are special roles (varmint, target, sustained rapid fire, etc.) where the benefits of a heavy barrel outweigh the drawbacks. But for general use the light barrel is better.

Besides, having a 5.56 rifle that weighs as much as a comparable 7.62 rifle has never made a lot of sense to me. But, maybe it’s just me.

Anyway, it would be nice if someone came out with a full range of .625 barrels and accessories. Just an idea for some small business looking for a niche in the AR marketplace.

Posted: 2/10/2006 1:16:02 PM EDT

[#13]

Quoted:
Quoted:
the cmmg bbls are .750 turned down to lw profile.

jt distributing shows a 14.5 true lw bbl. in their catolog for some time now.

So you are saying the same as Forest then, meaning it is lw except under the FSB?

basically.

Posted: 2/10/2006 1:17:06 PM EDT

[#14]

Quoted:
The CMMG barrels are light under the handguards and in front of the FSB (.625, superlight, whatever you want to call it), but under the FSB it is normal (.750). Bushmaster makes a true superlight (.625 FSB) as does Eagle Firearms and probably others.

wilson
jt distributing
colt

Posted: 2/10/2006 1:18:42 PM EDT

[#15]

Quoted:
I suppose the .750 barrel became “standard” when the Marine Corps adopted the Government profile barrel.

The problem is that there aren’t many .625 gas blocks or front sights out there. It would be easy to have barrels turned down to the proper .625 diameter but the other hardware just isn’t readily available.

And that’s a shame because the AR-15 is supposed to be a light rifle. I’ll grant that there are special roles (varmint, target, sustained rapid fire, etc.) where the benefits of a heavy barrel outweigh the drawbacks. But for general use the light barrel is better.

Besides, having a 5.56 rifle that weighs as much as a comparable 7.62 rifle has never made a lot of sense to me. But, maybe it’s just me.

Anyway, it would be nice if someone came out with a full range of .625 barrels and accessories. Just an idea for some small business looking for a niche in the AR marketplace.

yankee hill
bushmaster
larue tactical
p.r.i.
colt

all offer .625 fsb or gas blocks

Posted: 2/10/2006 1:26:18 PM EDT

[#16]

Quoted:
Quoted:
Quoted:
Does anyone know the weight or profile of the 16" CMMG lightweight barrel? I am wondering if it is lighter than the M4 proile because I have heard it is not true lightweight spec...

I have tried to call them but they must be on their way to Shot, so it was a no go.

Any info would be appreciated.

Thanks

Not trying to be a smart @%%, but I didn't know there was a lightweight spec. I thought it was a civilian market creation.

Doc

Well, pencil profile, A1 profile etc...original Colt A1 spec. The .625 or whatever.

Ok, that makes sense. I was thinking like a Busy Superlight.

Posted: 2/10/2006 2:13:41 PM EDT

[#17]

Quoted:
The CMMG barrels are light under the handguards and in front of the FSB (.625, superlight, whatever you want to call it), but under the FSB it is normal (.750). Bushmaster makes a true superlight (.625 FSB) as does Eagle Firearms and probably others.

However, the .625 FSB has the same or more metal in the barrel area, so the difference is negligible.

I have a superlight with .750 FSB and it is great fun. Turned down a standard barrel.

Posted: 2/10/2006 4:06:47 PM EDT

[#18]

Quoted:
Quoted:
The CMMG barrels are light under the handguards and in front of the FSB (.625, superlight, whatever you want to call it), but under the FSB it is normal (.750). Bushmaster makes a true superlight (.625 FSB) as does Eagle Firearms and probably others.

However, the .625 FSB has the same or more metal in the barrel area, so the difference is negligible.

I have a superlight with .750 FSB and it is great fun. Turned down a standard barrel.

Right. There isn't much more meat on the .750 FSB superlights. Still, they aren't true superlights because they don't use the .625 FSB. Really it's a matter of whether you really care or not about having a little more under the FSB. I personally think the .750 FSB superlights look kind of hokie.

Posted: 2/10/2006 6:23:01 PM EDT

[#19]

The problem, as I understand it, is that there are no "F" marked .625 FSB's, so if you are using an A2 upper you are GTG, but you may have issues if you use a flat top. No?

Besides, how much can that little bit really weigh? Unless you are trying for a A1 rebuild project, it's no big deal.

Posted: 2/10/2006 9:17:33 PM EDT

[#20]

Quoted:
The problem, as I understand it, is that there are no "F" marked .625 FSB's, so if you are using an A2 upper you are GTG, but you may have issues if you use a flat top. No?

Possibly. But I haven't run into them yet.

[ARCHIVED THREAD] - CMMG lightweight upper

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