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Old June 14, 2014, 01:30 PM   #1
RX-79G
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Why no M4 mids?

The M4 barrel is not legal to build a rifle out of without an SBR stamp, so civilians instead buy M4 barrels that have an extra 1.5" added in front of the site, or they buy 14.5" barrels with non-GI extended flash hiders welded on.

Why doesn't anyone make a mid length barrel that has the normal amount of M4 barrel sticking out ahead of the front site?

I realize the part that is for grenade launchers wouldn't line up, but 16" M4 barrels don't line up with bayonets. So if the M4 civilian barrel is cosmetic, why is no one making it in a mid?

I believe it would come out to a 16.5", once you get the right amount of barrel sticking out in front of the sight.
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Old June 14, 2014, 02:18 PM   #2
Willie Lowman
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don't know what you are asking for. Something like this?



Rockriver mid lenth A4

As for grenade launcher notches, they are useless on 99.9% of civilian rifles. My m9 bayonet attached correctly to the lug/around the flash hider. Bayonets are useless on 99.9% of civilian rifles too.

Last edited by Willie Lowman; June 14, 2014 at 02:29 PM.
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Old June 14, 2014, 02:34 PM   #3
RX-79G
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As I already said in the OP, the M4 barrel profile is cosmetic. Just wondering why those popular cosmetics don't come mid, since that would be the least funny looking, since it is all about cosmetics when it comes to M4s.
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Old June 14, 2014, 02:38 PM   #4
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Quote:
Originally Posted by RX-79G
Why doesn't anyone make a mid length barrel that has the normal amount of M4 barrel sticking out ahead of the front site?
I'm confused, I thought that's what a mid-length setup does already.

I was under the impression that that's what a 16" mid-length barrel is: It has the exact same amount of barrel ahead of the front sight as a 14.5" carbine-length M4.

I've never owned a 16" mid-length with a standard front sight post, but I've played with enough of them that I'm pretty sure they have the same amount of barrel in front of the sight that a 14.5" M4 has.

EDIT: I missed the previous post. So you're referring to the M203 cutout also? If the cutout stayed the same then it would be in the way of properly mounting the front sight. So I suppose you're talking about having the cutout be in the same place in relation to the front sight, and therefore be purely cosmetic? I suppose no one makes a barrel like that simply because, at that point, the rifle is different enough that its pretty pointless to add it. At least the M203 cutout is functional on a regular 16" carbine-length M4 profile barrel.
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Last edited by Theohazard; June 14, 2014 at 02:46 PM. Reason: Missed previous post by RX-79G
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Old June 14, 2014, 02:59 PM   #5
RX-79G
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A 16" M4 gives you the ability to mount an NFA M203, but not a simple bayonet. Therefore, it is pure cosmetic sillyness.

Just wondering why that same cosmetic silliness isn't applied where it won't look as weird - on a mid 16".
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Old June 14, 2014, 03:20 PM   #6
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I'm guessing it simply comes down to cost: The original reason to keep the M203 cutout and the bayonet lug on a 16" M4-profile barrel probably wasn't just for looks, it was also probably easier to make it the exact same as the real M4 barrel but with 1.5" added to the end. After that, customers got used to the look and so thats how most companies made their 16" carbine-length barrels.

But a 16" mid-length barrel is a completely different profile all around, so there's no manufacturing advantage to having an M203 cutout thats farther forward on the barrel just for looks. And because a 16" mid-length rifle already looks different enough from an M4 barrel, there's probably not a big demand for an M203 cutout thats purely for looks.

That's just my thoughts on it, but I could be wrong.
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Old June 14, 2014, 03:55 PM   #7
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I've been assuming that the 16" M4 profile became popular because it breaks up the look of all that barrel in front of the sight. I can't imagine an M4 16" is cheaper when you're usually charged more for it than heavy barrels - it requires more machining than a non-stepped barrel.
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Old June 14, 2014, 04:08 PM   #8
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Quote:
Originally Posted by RX-79G
I can't imagine an M4 16" is cheaper when you're usually charged more for it than heavy barrels - it requires more machining than a non-stepped barrel.
I suppose it all depends on how exactly they're manufactured. Maybe it's quicker and easier (and therefore cheaper) for a company that manufactures both 14.5" and 16" M4 barrels to just give all the barrels the exact same profiles and have the only difference be the length. That's just a guess though, I don't really know much about the specifics of the barrel manufacturing process.

And if it's not actually cheaper, then it was probably done because people want their rifles to be as close to what the military uses as possible. But with a mid-length that's probably less of an issue.

Quote:
Originally Posted by RX-79G
I've been assuming that the 16" M4 profile became popular because it breaks up the look of all that barrel in front of the sight.
I've never thought of that, but if that's true then it explains why they don't bother putting the M203 cutout on a mid-length: There's a lot less barrel in front of the sight so they don't have to worry about breaking it up.
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Old June 14, 2014, 05:11 PM   #9
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ArmaLite was making them up until a few months ago. I have one. When new, it looked just like an M4 except the handguard is too long, and no M203 cutout. I have a standard birdcage flash hider, F marked front sight, and a bayonet lug that is the correct distance from the flash hider for mounting a bayonet.

Rock River Arms sells a similar version too.. their Midlength A4 can be optioned with a standard front sight base and bayonet lug. My wife's AR is built around their barrel for it. Both are a heavy profile barrel and both are nice and accurate
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Old June 14, 2014, 05:47 PM   #10
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What about those barrels make them M4 profile? They look like govt profile.
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Old June 14, 2014, 06:02 PM   #11
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It is not cosmetic... even for regular folks. There are 37mm NON NFA launchers that use the M4 barrel contour for mounting. Just because you and your buddies, and a lot of people DONT use it for that purpose, doesn't make it cosmetic. AR MFG, at least the ones who take it seriously aren't going to contour a mid length barrel to look like an M4 because their is no purpose for it. The M4 contour is a standard most companies use to be as close as possible to using all the real attachments.

Heres a pic in this thread of a Del-ton upper with a 37mm launcher.

http://www.ar15.com/archive/topic.ht...f=124&t=183157

Not to mention people do own M203's
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Old June 14, 2014, 09:06 PM   #12
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Quote:
What about those barrels make them M4 profile? They look like govt profile.
Okay, I finally see what you are getting at.. I got out of your first post that you didn't care about the M203 cutout. I was mistaken.

I am unsure if anyone makes a midlength M4 profile barrel. I have never seen one. I suppose it's marketing.. if you go midlength, you lose a big chunk of the factory M4 look anyway, so the market for such a barrel would be pretty small.

I don't imagine it would be hard to get someone with a lathe to turn a cutout into a midlength barrel if you wanted to foot the expense.

The real problem with "utility" would be that the launcher would end up an inch and a half too far forward, you are supposed to use the magazine as a pseudo grip, and you would be unable to do so if the trigger housing for the launcher was too far away. Not to mention it would really look odd.

Me personally, if I wanted the smooth gas system and some kind of launcher, I'd just go old school and do a 20" government profile, with the old square M203 type handguard.
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Old June 14, 2014, 09:42 PM   #13
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Quote:
Me personally, if I wanted the smooth gas system and some kind of launcher, I'd just go old school and do a 20" government profile, with the old square M203 type handguard.
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You could still do a Mid system, just get a rail system and one of the launchers that attaches to a rail.
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Old June 14, 2014, 10:04 PM   #14
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I've been looking at this as no more than cosmetic, given the bayonet thing.

If you actually want to mount a launcher, a dissipator would work best. But those cosmetics are challenging, despite the advantages.
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Old June 15, 2014, 10:31 PM   #15
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PSA sells a mid length gas, lightweight, 14.75" upper that takes a standard length flash hider (pinned of course). Should fit your description.
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