M 4gery or not.

[Munster30]

I'm not sure what the facination is with M-4 configurations? Are there advantages to having a steped barrel?
I'm not meaning to flame here at all, just curious.
In my workplace we're allowed to use our personally owned rifles, as long as they're AR15/M16 platform and .223/5.56.
Just about everyone that carries their own in the car has an M4gery.

Personally I favor and carry a 16 inch heavy barrel, non chrome lined. I find it shoots well, the bullets end up where they're intended and the little extra weight from the heavy barrel doesn't bother me as we're not required to hump through the boonies.

[Kyrottimus]

I built my AR carbine to similarly reflect what I carried in the AF.

So mine really isn't so much an M4gery, but a GUU-5/P-clone.... a little spiced up.

But GUU-5/P-clone just doesn't have the dynamic-sounding title of "M4gery".


The stepped barrel has been rumoured to cool more quickly. I personally have no confirmation.

[Azrial]

My Colt does not have the step, it is a 16" HB.

[Bulwyeth]

The reason for the "step" is to attach a M203 Grenade launcher. Other than this, I am un-aware of any other function.

[Andy the Aussie]

Originally posted by Bulwyeth
Other than this, I am un-aware of any other function. ....hey it looks kewl.....;):biggrin:

In all honesty you are probably better off with the stiff 16inch full profile barrel or a 16 inch skinny. But to each their own....if folks are happy with the "203 step" then good luck to them....as long as no one is trying to sell it as anything other than what it is.

Andy:cool:

[Kyrottimus]

Originally posted by Bulwyeth
The reason for the "step" is to attach a M203 Grenade launcher. Other than this, I am un-aware of any other function.

That much is obvious...

however that purpose is only advantageous if one has an M203 (or compatible) grenade launcher.


Any other advantages (such as faster cooling, better barrel harmonics, etc.) are unnconfirmed myths at this point.

[Azrial]

Better barrel harmonics huh? I can see how it would create better barrel harmonics when it makes the barrel less rigid. It might give a tiny margin in barrel cooling due to the greater surface area of the barrel. But we are not talking much here. Most likely better to thread the entire outer barrel surface, ala Steyr AUG. Or, better yet fluting like my DSA!

I say it has one purpose and that otherwise it is a weakness.

[Munster30]

Originally posted by Bulwyeth
The reason for the "step" is to attach a M203 Grenade launcher. Other than this, I am un-aware of any other function. Me too, that's why I don't understand it, except for the "cool factor."

As for cooling and cool factor, a fluted HBAR, that's cool. :shades:

[101ABN327]

I guess the fascination with the M-4 is that it's what you see on the news every day. I like it because it handles well and you can shoot it all day!

Here is a pic of mine...

http://www.hunt101.com/data/500/19020ACU_M-4_001.jpg

[Kyrottimus]

Originally posted by Azrial
Better barrel harmonics huh? I can see how it would create better barrel harmonics when it makes the barrel less rigid. It might give a tiny margin in barrel cooling due to the greater surface area of the barrel. But we are not talking much here. Most likely better to thread the entire outer barrel surface, ala Steyr AUG. Or, better yet fluting like my DSA!

I say it has one purpose and that otherwise it is a weakness.

I totally agree.

Let me emphasize the:

Any other advantages (such as faster cooling, better barrel harmonics, etc.) are unnconfirmed myths at this point.

Of my previous quote.


Unconfirmed. Stuff I've heard from other people that usually caused me to scoff at them. The only other benefit I've known aside from the M203 capability is if you have the right-sized rack, that little groove makes it fit nicely in the rest. That IS if you have the right sized rack.


The only reason I built my XM117, GUU-5/P clone with the stepped barrel was because it was cheaper and IN STOCK at the choice location (pkfirearms.com)

[Azrial]

Kyrottimus, I was disputing the concept of better barrel harmonics, not you. I read your whole post, not just two words I wanted to argue about, like so many around here. We are in agreement.

[Kyrottimus]

Originally posted by Azrial
Kyrottimus, I was disputing the concept of better barrel harmonics, not you. I read your whole post, not just two words I wanted to argue about, like so many around here. We are in agreement.

I was pretty sure you got the jive of my post, I just wanted to make sure. :shades:

:beer: :beer: :beer:

[Azrial]

Originally posted by Kyrottimus
I was pretty sure you got the jive of my post, I just wanted to make sure. :shades:
:beer: :beer: :beer:
Yes, I understand Jive, but seldom speak it. :beer: :beer: :beer: :D

[Kyrottimus]

Originally posted by Azrial

Yes, I understand Jive, but seldom speak it. :beer: :beer: :beer: :D

Sweet

http://s41.photobucket.com/albums/e269/zaidenwinters/th_airplane7a.jpg

[cwo4uscgret]

http://iwantthatknife.com/Gallery/albums/military_guns/dpms_1.jpg

DPMS/PANTHER ARMS AP4 - .308 caliber version of an M4. Shoots nicely too!

[bykerhd]

I was looking for a new barrel for my AR and a stepped M-4gery barrel was for sale at a local shop at the right price. The step was not a factor in my decision. The manufacturers are offering the most popular combinations of options with the M-4 configuration barrel these days. I think that's a good part of why you are seeing so many M-4gery barrels around.

[Nitram68]

Originally posted by bykerhd
I was looking for a new barrel for my AR and a stepped M-4gery barrel was for sale at a local shop at the right price. The step was not a factor in my decision. The manufacturers are offering the most popular combinations of options with the M-4 configuration barrel these days. I think that's a good part of why you are seeing so many M-4gery barrels around.

Agreed. Initially everyone seemed to want them and now the market is full of them

Given a choice between two identical bbls with the only difference being one had the notch and the other not, I'd take it without. If fact, when I started buying Colts, the first one I bought was a 6721 (not the coveted 6920, which came later :biggrin: )

[chet]

When the 'forgery bug swept the nation a few years ago, I dumped a nice little flattop upper with a 16" fluted HBAR and a Vortex. The Oly barrel was not the greatest and the short site radius threw me a little having just come out of the Corps and carrying an A2 for the past 5 years. But, dangit, I wanted a M4 with all the bells and whistles!
But, eventually (and thankfully before I mispent a wad of cash), I figured out all them rails and gizmos are not all that necessary to getting hits. I guess they are handy if I am designating targets for Hellfires, . But I didn't really need it to have a nice handy lightweight carbine.
I knew I wanted a short barrel but 10" was just too much of a trade off in energy and blast. And since I didn't plan on any NFA type stuff, the HBAR really wasn't necessary, either.
What I decided on was a 14" pencil barrel with a permanently attached Phantom. I also got wanted a midlength gas system and midlength handguards since I had heard so many good things about uber light recoil and reliability. My other nod to the moderns (and it took me a while to weigh out even doing it) was to get a flattop. Instead of a carrying handle, I used the LMT A2 rear site in the event that my vision fails down the road and I need an optic. The detach carrying handle is a waste of space compared to the LMT.
Blast, oddly does not seem as bad as my old 16" HBAR/Vortex combo, and recoil really is lower. The Phantom does not have the "PING" report that the Vortex had either. Overall I am well pleased with the little carbine project.
Lower was an older PWA Commando. The upper as described is only available ready made (without rear site) in one place that I know of:

CMMG (www.cmmginc.com)
http://cmmginc.secure-mall.com/shop/images/669.jpg
(with the carrying handle in the CMMG photo).
Chet

[ttbadboy]

I believe the "step" on the M4 barrel can also be used to attach a 37mm flare launcher or "masterkey" shotgun (with SBS registration of course) in the civilian world. Few people do this.

I've even heard rumor that you can get a real 40mm M203 if you want (with SBR tax), just not the ammo for it. I have no idea if that is true and don't know of any actual examples of anyone doing it. The advertized price of the launcher is around $1800 before any applicable SBR tax, so it would take someone with a decent bit of money they wanted to spend on something that would be totally useless to them to find out...

To me the primary advantage of M4/govt profile barrels is not the presence of the "step", but that the weight of the barrel is considerably reduced since govt profles are turned down under the handguard as well. In a carbine/rifle designed to be fast handling, I much prefer a lighter front end than the HBARs provide. All my AR barrels are now govt profiles of varying lengths.

[Nitram68]

Originally posted by ttbadboy
I've even heard rumor that you can get a real 40mm M203 if you want (with SBR tax), just not the ammo for it. I have no idea if that is true and don't know of any actual examples of anyone doing it. The advertized price of the launcher is around $1800 before any applicable SBR tax, so it would take someone with a decent bit of money they wanted to spend on something that would be totally useless to them to find out...



A fixed bayonet is to 40mm GL what running the bayonet into a torso is to shooting 40mm ammo. :rofl:

You can get a 37mm sleeve for the 40mm so to shoot '37mm flares':wink:

[bykerhd]

from ttbadboy
To me the primary advantage of M4/govt profile barrels is not the presence of the "step", but that the weight of the barrel is considerably reduced since govt profles are turned down under the handguard as well.
I think you'll find that a good many of the M4gery barrels around are actually heavy profile under the handguards. I know the one I bought is.

[DYNOMIKE]

Originally posted by bykerhd

I think you'll find that a good many of the M4gery barrels around are actually heavy profile under the handguards. I know the one I bought is.

Ditto on Mine..
R/River M-4 Upper W/Heavy barrel under the H/Guards.. I actually wanted that setup so it's all good..

[ttbadboy]

If you have an "M4" barrel that has the step but is heavy under the handguards, then it is not a true govt M4 profile; it is some hybrid of an HBAR crossed with an M4 profile.

To me, govt profiles are instantly, noticeably lighter than HBARs, even without taking the handguards off to confirm the profile.

[1811GNR]

Originally posted by bykerhd
from ttbadboy

I think you'll find that a good many of the M4gery barrels around are actually heavy profile under the handguards. I know the one I bought is.

Colt calls this version the SOCOM or 6920/6921HB.

[Kyrottimus]

Originally posted by ttbadboy
If you have an "M4" barrel that has the step but is heavy under the handguards, then it is not a true govt M4 profile; it is some hybrid of an HBAR crossed with an M4 profile.

To me, govt profiles are instantly, noticeably lighter than HBARs, even without taking the handguards off to confirm the profile.

+1. Also you'll notice an "MP" stamped on the barrel. This stands for "Magnetic Paticle" inspected.

Meaning they run a magentic flux through it to detect any flaws and imperfections in the steel. It would not pass inspection if they found any.


If it doesn't have "MP" stamped on it after the manufacturer (like Bushmaster would be "B MP"; Colt would be "C MP", and so on), it's not Mil-Spec/Gov-Spec.

[bykerhd]

Yeah, I know that heavy barrel under the handguards is NOT mil-spec.
But, the discussion is about M4geries. Look-a-likes. Not the real deal.
Basically, what all the M-4 look-a-likes that are available to the general public are since none have been manufactured with the fun switch for us unworthy civilians. Some of the M-4geries around will have real military spec barrels, but I suspect that most will not. Either heavy profile under the handguards, 16" or 14.7" length instead of 14.5" or an incorrect flashhider or muzzle brake installed, maybe permanently, to be legal.
You can duplicate the correct appearance if you want to register it as a Short Barrel Rifle and get the tax stamp. Or, you can get as close as you can afford and live with it.

[airground]

Not an M4 but my GUU-5/P clone....liteweight 1/7 pencil bbl so I can shoot all the different 5.56....


http://www.gunboards.com/forums/uploaded/jeremy/2006822213641_rifle%20006.jpg

[jrgunman]

If it doesn't have "MP" stamped on it after the manufacturer (like Bushmaster would be "B MP"; Colt would be "C MP", and so on), it's not Mil-Spec/Gov-Spec.

SO WHAT ARE ROCK RIVER BARRELS? THEY ARE GOV`T, MILSPEC BUT DO NOT HAVE THOSE MARKINGS, YOU`LL BE HARD PRESSED TO FIND ANY MARKINGS ON A RRA BARREL, JUST NUMBERS ROLLED INTO THE BARREL, UNDER THE BARREL NUT AREA, THEY USE WILSON BLANKS AT THE ROCK

[Kyrottimus]

Originally posted by jrgunman
If it doesn't have "MP" stamped on it after the manufacturer (like Bushmaster would be "B MP"; Colt would be "C MP", and so on), it's not Mil-Spec/Gov-Spec.

SO WHAT ARE ROCK RIVER BARRELS? THEY ARE GOV`T, MILSPEC BUT DO NOT HAVE THOSE MARKINGS, YOU`LL BE HARD PRESSED TO FIND ANY MARKINGS ON A RRA BARREL, JUST NUMBERS ROLLED INTO THE BARREL, UNDER THE BARREL NUT AREA, THEY USE WILSON BLANKS AT THE ROCK

In order to be "Mil-Spec" the unit must meet military standards. The military requires the markings of a barrel, receiver, etc to be plainly visible without any stripping of the firearm; at least last I checked.


While the RRA barrels are made to meet the physical specs of the military barrels, if their marking locations aren't in compliance with military requirements, then technically they are NOT mil-spec.

Also, if it has an NSN, it's definately DoD spec. If not, then no.

[HawaiiFALer]

Originally posted by Bulwyeth
The reason for the "step" is to attach a M203 Grenade launcher. Other than this, I am un-aware of any other function.
This is the honest, gospel truth, as dictated by the U.S. Army Ordnance Corps. :biggrin:

[mstennes]

There were a batch of 14.5 medium contour barrels made for SF types but they still have the 203 grove. If I were to build another one (I have 3 of these on hand I built now) would be a 16" middy with LaRue HG's. Get it chrome lined The higher velocity is worth it as you have to have 16" unless you go SBR which if you dont makes you pinning your Phantom or Vortex on it. I would go flat top to be able to mount any optics/sight you want. A middy will shoot a little nicer and if you use irons gives you a little more sight radious.

[RockyMtnTactical]

It's just a good compromise between an HBAR and a superlight... unless it's not light under the handguards, then it's just for looks.

[Mortech]

My OlyArms K3B-M4 is lighter under the handguards , that makes it a joy to tote after lugging a HBAR around for years .

http://www.delsol.net/~madmoe1/Max2a.jpg

[Wolf Spyder]

I am not a subject material expert on Mil-Spec.

However,

I know that a thicker barrel has better harmonics than a thinner barrel.

I also know that the M-4 cut is counter productive to barrel harmonics and accuracy.

I also know that a mid length gas system is better than a carbine gas system.

And last but not least Chrome is King. Chromed barrel, Chromed chamber, Chromed bolt, Chromed carrier. At the very least it makes cleaning so much easier.