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Old November 15, 2013, 06:13 PM   #1
F23Blackwidow2
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18" Rifle Length AR-15 Barrel

Hello everyone,

I'm looking into putting together a SPR AR build, and want a 18" barrel with a rifle length gas system. Problem is, I'm on a budget, and I want the barrel to be relatively light weight.

So far I have found the Rainier Arms Match Grade SPR, but it's to heavy for what I want, 2lbs 9oz. https://www.rainierarms.com/?page=sh...roduct_id=2902

The Rainier Arms Mountain Series 18"
https://www.rainierarms.com/?page=sh...roduct_id=4049

And the AR -Stoner 20" fluted barrel. The problem I have with this is that it's not from a company I know of, and I want a accurate long lasting barrel.
http://www.midwayusa.com/product/577...vc=subv1794051

So the 3 barrels I found all have problems for me. The Rainier Match is to heavy,
The Rainier Mountian barrel is expensive, and the AR-Stoner barrel is 20" and from a company I have no experience with. Plus, I'm not sure if I want a 20".

Are there any other options in the $200-$275 range? I care more about being light weight then cost though, so I'm leaning towards the Mountian series.

Rifle length is a must. I have my mind set on that.

Thanks,
F23
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Old November 15, 2013, 11:36 PM   #2
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The fact you want it to be rifle length limits certain aspects. I have a daniel defense barrel that is very very nice and doesn't weigh much but I had to get it in a carbine length.
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Old November 15, 2013, 11:51 PM   #3
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Why does it have to be rifle length?
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Old November 16, 2013, 01:25 AM   #4
Fishbed77
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Quote:
Why does it have to be rifle length?
All true SPR barrels are rifle length by definition.
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Old November 16, 2013, 08:27 AM   #5
F23Blackwidow2
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In partial both to the cleaner running aspect of rifle length gas systems, and the reduced recoil. I want to be able to make follow up shots as soon as I can. Plus, I have heard they cause less wear on the gun, although I have not substantiated that claim.

Thanks to everyone who has responded so far.

F23
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Old November 16, 2013, 09:54 AM   #6
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I might be biased as I set the specs for this barrel, but I do believe it is one of the best barrels on the market: http://www.carbonarms.us/AR-15-Upper...AR-barrel.html
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Old November 16, 2013, 02:35 PM   #7
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I just bought an AR-Stoner barrel from Midway. That name seems to be the house brand so I have no idea who made it, but decided to trust the Midway name for quality.

I bought a 16-inch stainless fluted with .223 Wylde chamber. The fluting is certainly deep and lightens the barrel and let's face it, I will not be able to tell if is slightly substandard in accuracy.

Anybody have any personal experience with AR-Stoner barrel?

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Old November 16, 2013, 05:06 PM   #8
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The AR-Stoner's are hit and miss. The one you have seems to be perfectly suitable. The 300 BO barrels I have tried are also decent, 16" stainless. The 16" mid-length was a piece of metal I should probably not even talk about. Seems the stainless ones are okay, the carbon steel ones, not so much.
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Old November 17, 2013, 09:57 AM   #9
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Nordic 18" Rifle Gas Wylde. I have one, no problems so far.
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Old November 17, 2013, 03:19 PM   #10
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Thanks for the suggestions, but are there any non-match profile barrels out there? I have yet to find anything except the Rainier Arms Mountain Series barrel that is 18", rifle length, and does not have a match profile (it has a gov't profile) barrel.

It can't be the only one.

Has anyone heard of Black Hole Weaponry?


Thanks,
F23
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Old November 17, 2013, 05:00 PM   #11
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http://www.superiorbarrels.com/Our%20Barrels.htm

It has the spr profile, but it's heavy and expensive.
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Old November 17, 2013, 05:42 PM   #12
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Quote:
Thanks for the suggestions, but are there any non-match profile barrels out there?
There's no such thing as a "match profile" barrel. Not sure what you mean by that.

Typically, and SPR will have an SPR-profile barrel that uses a rifle-length gas system. It may be a "match-quality" barrel, which makes sense, because an SPR is supposed to be a precision rifle. It's not a very lightweight barrel profile, but is certainly lighter than a heavy barrel or bull barrel profile.
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Old November 17, 2013, 07:03 PM   #13
tirod
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Bull barrel = match barrel.

From wikipedia:
Quote:
Barrel: An 18-inch (457 mm) threaded-muzzle match-grade free floating stainless steel heavy barrel with a 1:7 (178 mm) rifling twist ratio is standard for the SPR. The barrels are manufactured by Douglas Barrels with a special contour to maximize accuracy and to minimize weight. An OPS Inc. muzzle brake and collar (to align the OPS Inc. 12th Model Suppressor) is installed with the barrel.
That "special contour" is likely somewhere between standard GI and bull, which means it's not all that light. IIRC its something close to "recon"/"socom" profile that ARP sells (check for availability.)

Since it's a custom build to replicate the DEVGRU MK 12 that is phasing out, it's not likely a big seller and is produced in small batches nearly pre sold. I had the same issue buying a 16" midlength 6.8 in the day, but it was due to being extremely popular at the time. Mine was one of about 30 in that batch. Had I wanted a standard GI barrel, I could have saved 50% and got it delivered in days.

But what fun would that be? Good luck on your search, it might likely just need to be ordered and then wait for it.
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Old November 17, 2013, 07:42 PM   #14
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"Bull" and "match" are definitely NOT equivalent terms.

Black Hole does make very good barrels, most who shoot a lot would consider them to be a step above Mil-Spec.

When the term "match" is used, you kind of have to figure out if the descriptor is for 3Gun, Hi-power, Benchrest, etc. There are some pretty significant differences. Those who shoot 3Gun look for 1 MOA or better with some longevity, low recoil impulse, reliability and durability. When something has been proven in 3Gun, it is likely much better than some other configuration that has not.
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Old November 17, 2013, 07:50 PM   #15
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Save your money and get the one you want. You'll be glad you did.
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Old November 17, 2013, 11:07 PM   #16
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I think there's a reason you don't see a lot of rifle length 18" barrels . It's because that only leaves you with 6" of dwell time . You will need a larger gas port or tinker with buffer and springs to get the rifle to cycle at it's best .

Dwell time is pretty important . If the bullet leaves the barrel before enough gas has been redirected down the gas tube there will not be enough pressure to cycle the bolt . Most of the time resulting in short stocking . It's one of the reasons SBRs are so finicky .

I'm not saying it won't work , just saying it's not what's best . There's a common theme when it comes to dwell time and anything under 7" is going to take extra work to make it work .

14.5" carbine length
16" to 18" mid length
20" and more Rifle length

I'm thinking there's a reason all these have a 7-1/2" to 9" dwell time .

Yes 16" barrels come in carbine length but they are much harder on the action then a 16" midy . For those of us that have both . Ever notice how much farther your carbine throws the brass compared to the midy .Thats the extra 1.5" dwell time allowing more gas down the gas tube rocking the BCG back . Thats where tinkering comes in And who doesn't like to tinker with there AR
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Old November 17, 2013, 11:11 PM   #17
Fishbed77
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Quote:
Bull barrel = match barrel
No.

A bull barrel may be "match" quality, but not all "match" barrels are bull barrels.

But then again, calling any firearms component "match" is just marketing speak, since there is no empirical standard for what constitutes a "match" component.
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Old November 18, 2013, 07:21 AM   #18
F23Blackwidow2
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Sorry for the confusion. When I said match profile I did mean bull. Sorry about that.
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Old November 18, 2013, 10:18 AM   #19
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Quote:
I think there's a reason you don't see a lot of rifle length 18" barrels . It's because that only leaves you with 6" of dwell time . You will need a larger gas port or tinker with buffer and springs to get the rifle to cycle at it's best .
Completely false! However, the perpetuation of the myths on the internet may have something to do with it.
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Old November 18, 2013, 11:47 AM   #20
Metal god
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Quote:
Completely false!
Please explain how that is "completely" false .

Quote:
You will need a larger gas port or tinker with buffer and springs
Other then the above saying you WILL need rather then what I should have said you MAY need . I thought I gave a good explanation why it's not the best set up . I did not say it was bad , wrong or would not work . Are you saying dwell time ( the length of barrel past the gas port ) is not important on how the platform operates ? Are you saying a carbine length gas system on a 20" barrel will work just fine with out any mods ? Are you saying that's just not the reason you don't see many 18" barrels with rifle length gas systems ?

I'm not trying to be a jerk but if I'm completely wrong . I'd like to know if it's everything I said or just part . No need for me to keep saying it if it's flat out wrong .
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Old November 18, 2013, 12:10 PM   #21
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It is a system. Gas port size, leakage, gas system length, gas key fit, gas rings, gas volume available, all have an impact on the operation.

The typical "Mil-Spec" parameters are over-gassed by about 30%. Dwell time is not the only parameter. 16" and 17" guns with rifle length gas will run just fine using Mil-Spec ammo. Most of the gas blocks leak like a sieve, so people pump in more gas instead of fixing the issue. With an 18" barrel and rifle length gas, you can actually drop the gas port size and still get 100% function. A carbine length gas system on a 20" is way too much (volume and pressure) and will cause other problems, some of which many will confuse for over-pressure ammo.

Now, when you want to use steel cased ammo, or underpowered ammo, then you have more leakage and thus you need more gas volume.

"Mil-Spec" worshippers are probably the largest reason you don't see rifle gas on 18". 18" barrels are not common in the Military, but they are likely the best all-around version. The main reason they are even out there is because the 3Gunners kept screaming for them. I've run several Monte Carlo analysis models and with rifle gas, 18.5" is about optimum when all the parameters are considered.

Sure, changing "will" to "may" is better.
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Old November 18, 2013, 12:37 PM   #22
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DS Arms-

http://www.dsarms.com

I'm a HUGE FAN of their products and have 2 of there uppers, and am looking to buy 2 more...have never had any issues with products, and they eat whatever I feed them!

18" is a tuff order for the price, I am looking to get this:

http://www.dsarms.com/p-12714-dsa-zm...eed-ramps.aspx

...for my next AR build as I have a 14.5 and a 16 ...this one I wanted for some longer distance mount a TR20-2G on it and I'll be good to go

if you were interested in JUST the 20" barrel I'm sure they would sell that...just their barrels run about $140 - $230 depending on the material...call them and tell them what your looking for, and order your specifics!
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Old November 18, 2013, 12:40 PM   #23
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Thanks for the detailed explanation .

However
Quote:
It is a system. Gas port size, leakage, gas system length, gas key fit, gas rings, gas volume available, all have an impact on the operation.
Yes but I did assume all other aspects of the system were working fine and was commenting gas volume available . I think I stand by my 6" of dwell is on the short side and "could" cause problems .

Just to confirm ( The typical "Mil-Spec" parameters are over-gassed by about 30%. ) I'm assuming thats the 14.5" barrel with carbine length gas system . That would make the 16" carbine way WAY over gassed ?

The other thing to confirm would be . If you take a complete mil-spec M4 and replace the barrel only with the 18" rifle gas with no other mods . The gun will shoot all rounds put through just as well as before the barrel change ?
Same : buffer tube , buffer , buffer spring , gas port size , BCG .

Meaning there should never be anything you would need to do to get that setup working better ?
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Old November 18, 2013, 11:25 PM   #24
F23Blackwidow2
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I believe MarkCO is right. I have heard that the 18 inch rifle length systems are sometimes even more reliable than 16 inch mid lengths, if not just as good. The size of the gas hole is different, and the bolt definitely gives the bullet enough time.

Thanks,
F23
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Old November 19, 2013, 01:40 AM   #25
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I agree as well when it comes to the whole gas system and all the things that need to happen for the platform to work . My point in my OP was quite narrow . I was just making sure you knew there was more to that type of build then just throwing the thing together with any carbine or A2 parts . you "may" need to tinker with it to get it running perfect . Thats all .

I want to see pics when your done
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