16" or 20" AR?


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kennygarza
February 23, 2006, 04:55 PM
I'm looking into getting an AR-15, but I can't decide on which length to get it in. If I go the 16" route, it will have the collapsable stock on it. This will be mainly just my fun gun. Shots will be at 300 yds. max., usually around 100 yds. I'd like to hear from some of you that have either one, pros and cons. I like the idea of a handy carbine, but I also want something that I can reach on out there with from time to time.
Any info would be greatly appreciated.
KG

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Rem700SD
February 23, 2006, 05:15 PM
My vote is for the 16" bbl. It's much handier, lighter at the fore-end, and better as a fun gun. The downside is that it will be a little louder, and the velocity will be lower. I think the accuracy will be the same.
My.02
Dan

ocabj
February 23, 2006, 05:20 PM
Whichever you get, make sure it's a 1 in 7" twist so you can maximize use of the heavier weight bullets, specifically the 75 and 77 gr offerings from Hornady, Nosler, and Sierra.

355sigfan
February 23, 2006, 05:26 PM
The 16 inch is my choice. The 20 inch gun is less manuverable in tight spaces. The 223 is not a long range round and is more at home in a carbine.

I prefer the 1 in 7 twist but you can do fine with a 1 in 9. The heavy bullets are great but the 69 grain loads will work in a 1 in 9 and their heavy enough.
Pat

_N4Z_
February 23, 2006, 05:35 PM
I used 20" in the Army and for 300 yard or meter shots, it filled the bill nicely. To me 300 meters with iron sights IS long range.

If your looking for a fun toy to impress yourself with at the range (out to 300m) go 20. If your wanting it for urban warfare, home defense, yada yada sis boom bah, go 16. Probly not much diff between the two but I prefer the longer barrel.

Jacobus Rex
February 23, 2006, 05:35 PM
I went with the 16" on my AR for compactness reasons. Although, I use an A2 stock. I like the shorter front combined with the longer stock.

I don't think that the 16" is a disadvantage at realistic ranges. Most of my shots are taken about 100 yards or less.

For a varmit/target gun, I'd use the 20" or longer. Other than that, I'd stick with a 16"

I went with 1 in 9 twist as the best overall and good for shooting cheap 55 grain stuff.

engineer151515
February 23, 2006, 05:41 PM
Sold my 20". Have two 16".

My $0.02.

Get the 16" then buy a 20" upper later (if you still feel the need).

MechAg94
February 23, 2006, 05:48 PM
I got a 20" Armalite. It seems plenty light and handy for me, at least compared to an M1A or my Vepr. My Dad has a 16" Colt sp1 and that is a handy gun. Yeah, I do think it depends on what you want it for. I like the 20" though.

ArmedBear
February 23, 2006, 05:54 PM
I've been pondering the same thing. And I already have a stainless Ruger Ranch Rifle, which is a handy little thing and fine at 100 yards.

I've been leaning towards 16" for the AR, though I'd like a straight heavy barrel, not an M4, since I have no plans to add a grenade launcher. I do see an accurate 20" in my future, though.

But what about the buttstock? I suppose my wife will shoot it now and again, so adjustable could be nice. But is there any other reason to get an M4 or CAR stock? If so, which of those? (Note: I'm too cheap to get a SOPMOD).

Do carbine stocks have FTF problems with 20" uppers? Or is that just an unconfirmed rumor?

Bartholomew Roberts
February 23, 2006, 06:32 PM
A 16" barrel is capable of wearing out targets at 300yds with no problem at all. The only real change the 20" gives you is a longer sight radius in the stock configurations of each rifle (though you can make a 16" rifle with the same radius as the 20") and about 100fps more velocity.

Do carbine stocks have FTF problems with 20" uppers? Or is that just an unconfirmed rumor?

20" barrels have no problems with collapsible stocks.

georgeduz
February 23, 2006, 06:38 PM
yes i think 300meter i about the limit you can see a human size target.i have a 20in barrel.but i just order a 16 in upper kit from olyimpic arms.i dont think there be much different.i,ll let you know when i get it to the range.they claim to have very good barrels so we will see how it compares to my colt target match 20in .

Zach S
February 23, 2006, 06:40 PM
I prefer a 16" with a collapsable stock.

rangerruck
February 23, 2006, 06:41 PM
if you are not going for kill shots outside of 300 yds, then the 16 will be lighter, funner, more accurate, stiffer.

ocabj
February 23, 2006, 07:01 PM
Better yet, get an 18".

http://www.ocabj.net/photos/firearms_personal/IMG_4167_altered_500.jpg (http://www.ocabj.net/gallery/mk12mod1)

BillL223
February 23, 2006, 07:15 PM
First AR was a BM 16" V-Match. 2nd was a 20" JP upper on a BM lower. Both were good however I rebarreled the 16" with a 20" cut down to 18". This seemed better. Sold that, got a new JP 18" upper on a BM lower. This combo of a 20" gas system on a 18" barrel is great.

ArmedBear
February 23, 2006, 07:30 PM
That's my other question.

Is one gas system more desirable than another?

How reliable is the 16" with 20" like a Dissipator? Is a mid-length worth the trouble of having a non-standard foreend?

ocabj
February 23, 2006, 07:47 PM
That's my other question.

Is one gas system more desirable than another?

How reliable is the 16" with 20" like a Dissipator? Is a mid-length worth the trouble of having a non-standard foreend?

The two reasons why the midlength gas system caught on is because of the longer sight radius (compared to the original carbine length) and the claims that a midlength system is gentler on the upper receiver, bolt, and buffer assembly.

As far as the reliability of having a full length gas system on a 16" barrel, it will function just fine.

MatthewVanitas
February 23, 2006, 07:54 PM
How reliable is the 16" with 20" like a Dissipator?

A Dissipator will be no different in reliability from any other AR-15 carbine. The Dissipator has the exact same placement of the functioning gas block as on a carbine (which ends up being under the handguards). The front sight base does not serve any gas-bearing function, it's just there to hold the front sight out in the 20" position.

If you get a Dissipator, strongly consider getting a M4-profile or fluted barrel. Everyone with an HBAR Dissy says that it's muzzle-heavy, but I got the M4-profile Dissy barrel from Bushmaster and it balances just great.

If you like the fixed stock, but want a little bit shorter than the A2, consider getting an A1-length stock. Cavalry Arms makes them new-prouction for a good price. I just bought a few of them, very happy with the size, and quality is good though buttplate is not mil-spec. PM me if anyone wants one of my spare A1 stocks for cheap.

Ditto what everyone has said thus far IRT 20" vs. 16". Though I somewhat wish that I'd bought one of those 20" Colt M16A1 uppers for the retro-coolness.

-MV

Rob1035
February 23, 2006, 08:12 PM
if you are not going for kill shots outside of 300 yds, then the 16 will be lighter, funner, more accurate, stiffer.


Not to disagree, but how will a shorter barrel and sight radius be more accurate?

cgv69
February 23, 2006, 08:14 PM
As with most things, it depends on what you are going to be doing with it. In your case, for your purpose, it doesn't really matter. Either will suit your purpose just fine. I would just get the one that floats your boat the most. Before you make up your mind, here's some stuff you should know...

A longer barrel does not mean better accuracy. Just more velocity. That's helpful if you are shooting at live targets but for punching paper, it doesn't matter.

In the AR platform, a 20" barrel does buy you a few advantages. The first one only matters if you will be using the iron sights. If you going to use the iron sights, the longer sight radius of the 20" barrel will help, especially at 200-300 yds.

The other is the gas system. A 20" barrel uses a "rifle" length gas system. A 16" barrel generally uses a "carbine" gas system. The short version of all this is the rifle gas system will have a little less felt recoil and they are generally a tad bit more reliable.

A happy middle ground is a 16" barrel with a "Mid-Length" gas system. With a mid-length gas system, the gas port (and hence FSB) is 2" further out towards the end of the barrel. This gives you the compactness of a 16" carbine but recoil and site radius closer to a rifle length barrel.

One last thought. Collapsible stocks are "cool", especially because they were so "evil" for 10 years. They can be useful if you wear body armor or need a very short LOP for some reason but that said, a fixed stock, especially a A1 length, is so much more enjoyable to shoot. Its just really hard to get a good check weld on a typical collapsible stock and even if you do, chance are it won't be comfortable.

In short, I think a 20" rifle with a fixed stock will provide you with the most enjoyment at the range but if a 16" carbine is what you want, then go with that. The best rifle in the world may not be any fun if its not what you want. As long as it's a quality built carbine, it will serve you and your purposes just fine.

Bartholomew Roberts
February 23, 2006, 08:31 PM
Is a mid-length worth the trouble of having a non-standard foreend?

The bolt and cycle of the AR15 were designed to work with the 20" rifle (http://www.findarticles.com/p/articles/mi_m0BQY/is_11_51/ai_n15402262). On a 20" rifle, the gas port pressure is around 12-15k psi and located about 13" down the barrel. In a carbine, the gas port pressure is about 28-30k and is located about 9" down the barrel. This means that the carbine cycles harder, faster and is trying to extract the fired case while pressures are higher than they are in the rifle.

A midlength drops port pressure to around 18-21k and moves the distance out another 2". These are pretty well understood facts. Just shooting a carbine and a midlength side by side you can tell the difference in the smoother recoil of the midlength. From a practical aspect, this should mean that lifespan and parts breakage on a midlength should be more rifle-like than carbine-like. Just watch the training video of the XM16E1 and you should be able to understand why the amount of gas pressure and the distance it travels is relevant to the functioning of the rifle.

Also, while a midlength isn't exactly standard there are literally dozens of firms making midlength furniture, so parts shouldn't be an issue at all.


As far as the reliability of having a full length gas system on a 16" barrel, it will function just fine.

Based on what I have read, 16" barrels with rifle-length gas systems suffer from some of the same short dwell time and reliability issues that plague the 10.5" shorties. With so little barrel past the gas port, the bullet leaves the barrel and the pressure drops before the gun can get enough gas to cycle reliably. If you go this route, you need somebody who knows how to open up the gas port to the correct diameter and a muzzle device that creates some backpressure isn't a bad idea either. However, a better response is either a midlength or carbine gas system under the handguards.

17" is about the shortest you can go and use a rifle-length gas system without adversely affecting reliability.

355sigfan
February 23, 2006, 09:21 PM
The bolt and cycle of the AR15 were designed to work with the 20" rifle (http://www.findarticles.com/p/articles/mi_m0BQY/is_11_51/ai_n15402262). On a 20" rifle, the gas port pressure is around 12-15k psi and located about 13" down the barrel. In a carbine, the gas port pressure is about 28-30k and is located about 9" down the barrel. This means that the carbine cycles harder, faster and is trying to extract the fired case while pressures are higher than they are in the rifle.

A midlength drops port pressure to around 18-21k and moves the distance out another 2". These are pretty well understood facts. Just shooting a carbine and a midlength side by side you can tell the difference in the smoother recoil of the midlength. From a practical aspect, this should mean that lifespan and parts breakage on a midlength should be more rifle-like than carbine-like. Just watch the training video of the XM16E1 and you should be able to understand why the amount of gas pressure and the distance it travels is relevant to the functioning of the rifle.

Also, while a midlength isn't exactly standard there are literally dozens of firms making midlength furniture, so parts shouldn't be an issue at all.



Based on what I have read, 16" barrels with rifle-length gas systems suffer from some of the same short dwell time and reliability issues that plague the 10.5" shorties. With so little barrel past the gas port, the bullet leaves the barrel and the pressure drops before the gun can get enough gas to cycle reliably. If you go this route, you need somebody who knows how to open up the gas port to the correct diameter and a muzzle device that creates some backpressure isn't a bad idea either. However, a better response is either a midlength or carbine gas system under the handguards.

17" is about the shortest you can go and use a rifle-length gas system without adversely affecting reliability.

Actually the little guns have a larger gas port and have enough gas. The problem is that there is not enough dwell time before the pressure drops and the bolt carrier starts to move back. The case is still swelled and this casues extraction difficutlities with the little guns. Hence the reason for the pig tail. It does not add gas but rather increases the dwell time and allows pressures to drop.
Pat

Bartholomew Roberts
February 24, 2006, 12:06 AM
Actually the little guns have a larger gas port and have enough gas. The problem is that there is not enough dwell time before the pressure drops and the bolt carrier starts to move back. The case is still swelled and this casues extraction difficutlities with the little guns. Hence the reason for the pig tail. It does not add gas but rather increases the dwell time and allows pressures to drop.
Pat

It is kind of a chicken or the egg deal. You can't use a normal carbine-size gas port on a shorty even though the gas port is in the same location because the bullet will exit the barrel before you get enough gas.

So to fix that, you open the gas port so that the gun gets enough gas to cycle before the bullet leaves the barrel; but in a 10.5" barrel this means the gun is trying to cycle while pressures are still too high. So now you throw in patchwork fixes like pigtails to delay the time it takes for the gas to hit the carrier or heavy buffers to slow the cycle.

I think the best fixes for direct gas guns are solutions like the Krink flashhider or suppressors that create enough backpressure that you can run the shorty with a smaller gas port; but even then an extra inch or two of barrel can be helpful to reliability.

355sigfan
February 24, 2006, 12:10 AM
I will agree that the shortguns are far more difficult to keep running reliably. I would like to see how the new gas piston guns do with short barrels.
Pat

kennygarza
February 24, 2006, 08:19 PM
Thanks for the input, guys. I will probably be going with the mid-length Rock River... unless someone can convince me otherwise.
KG

355sigfan
February 24, 2006, 08:23 PM
IF you can find a Colt get it. But I have heard good things about RRA for the most part.
Pat

Sactown
February 24, 2006, 08:27 PM
I'd go with a 16 midi.

cgv69
February 24, 2006, 08:55 PM
Thanks for the input, guys. I will probably be going with the mid-length Rock River... unless someone can convince me otherwise.


Good choice. Just a few more things...

1. If you want a 16" middy then ignore the "Colt" advice. Colt makes some nice stuff but they have yet to get with the times and make a barrel with the mid-length gas system. I wish they would but they don't
2. What ever barrel you get, make sure it's chrome lined. It really does make a difference in both reliability and ease of maintenance.
3. Do not get an HBAR profile barrel, especially in a mid-length or or rifle gas system. Not only do they weigh to much but they also screw up the balance of the weapon, especially if you go with a collapsible stock.

I have a RRA 16" middy barrel that is chrome lined and was turned down by ADCO to a government profile. Even with the re-profiling, the gun is still a little front heavy. Luckily I use a fixed A1 length stock on it so it's not too bad but I did put it on another lower with a collapsible stock and the balance sucked. If it was an HBAR, I guarantee I would have hated it with either stock.

When I bought it, it was one of the only choices out there for a 16" middy and so far, it has performed well. That said, I think there are better choices out there now. Saber Defense makes a nice middy that comes profiled and chrome lined and can be had with 1/7 twist and M4 feedramps. Both are nice options if you plan to use and of the newer heavier rounds. (standard ramps and 1/9 is fine for your typical 55gr loads.). Bravo company is also getting ready to release some 16" middy uppers that should be really nice.

Spend some time on AR15.com. Look around and become familiar with what's available before spending your money.

355sigfan
February 24, 2006, 09:24 PM
Beg to differ. Colt makes the most reliable short guns period. Been around the block a few times and seen many non colt guns choke in training. Its rare for a Colt to choke. Ignore the previous posters advice.
Pat:neener:

cgv69
February 24, 2006, 10:16 PM
Beg to differ. Colt makes the most reliable short guns period. Been around the block a few times and seen many non colt guns choke in training. Its rare for a Colt to choke. Ignore the previous posters advice.


Dude, kennygarza wrote that he decided to get a 16" barrel with mid-length gas system. As you should be aware, Colt does not make any barrels with a mid-length gas system so there for your advice to buy a Colt is useless to this conversation.

Try to keep up. ;) :neener:

355sigfan
February 24, 2006, 10:20 PM
A mid length gas system is a answer to a non problem at least if you buy Colt. :neener:
Pat

Alex45ACP
February 24, 2006, 10:24 PM
I went with a 16" mid length.

I got this one: http://www.talonarms.com/talonarms/index.php?main_page=product_info&cPath=127&products_id=311

Bartholomew Roberts
February 25, 2006, 12:08 AM
Speaking of which, how are you liking the Sabre rifle?

cgv69
February 25, 2006, 09:54 AM
A mid length gas system is a answer to a non problem at least if you buy Colt.

Do you own a Mid-length carbine? Have you ever even shot one? As a person who owns both a Colt 14.5" carbine and an RRA 16" mid-length carbine I can tell you from first hand experience that the Mid-length gas system is the right answer that Colt should have been smart enough to come up with in the first place. I will agree that a well built carbine gas system weapon (Colt or otherwise) can be a very reliable and effective weapon but the mid-length gas system has a number advantages and is the better design IMO.

In an effort to keep this thread from getting too far off track or into a full on pissing match, that will be my last reply about that. :D

Stevie-Ray
February 26, 2006, 12:43 AM
I'd opt for the 16. I bought a shorty, because if I want to reach out to touch something, I've got a heavy-barrel SAR-48.

Seraph
February 26, 2006, 02:24 AM
A friend I work with recently tempted me to get into AR-15's. In considering what to get for my first, I immediately dismissed Colt as an option, because I already knew from my experience with M16-A2's that Colt knew how to make them. To maximize the experience, I decided to assemble my own 16" carbine from stricly non-Colt parts, but I had to promise my Mrs. that I would keep the project cost down. I bought a very nice RRA stripped lower at Knoxville's best gun store, Coal Creek Armory;) . I liked the lower receiver enough that I determined to finish it out with a lower parts kit and an A2 buttstock kit ordered through RRA's website. FWIW, the lower parts seem to be identical to those of Colt, Bushmaster, Armalite, and, for all I can tell, these may all really be made by only one or two manufacturers. For the upper half, I looked at a lot of options, and was tempted by some of the sexy, expensive ones, but kept my word to the Mrs. on the budget, because I'm not crazy:o. Fortunately, I was able to make the excuse with my wife that I had to spend a LOT of time lurking at ARFCOM, and browsing lots of AR-15 industry vendor sites, in order to put together the best possible upper half within the promised budget:evil: . It was interesting to consider all the available options, but I carefully chose a not-so-interesting option, that of a complete RRA CAR A4 upper, with mid-length gas system, and Wilson 16" stainless HBAR, with 1X8" twist and .223 Wylde chamber, which I ordered from Legal Transfers (ar15sales.com) (thanks, Pete). Effectively, I will end up with a RRA Elite CAR A4, with an A2 buttstock. I'll have to wait a couple of weeks for delivery of the upper, as barrels seem to be back-ordered at RRA, which means I'll also have to wait to find out whether the RRA carbine will prove to be the quality/performance/cost value I hope I've correctly reasoned it will be. That's OK, because I'll have to wait until I get payed again before I can buy the requisite case of M855. I'd love to do some kind of high round count torture test, but I'm going to need the money for another carbine, because watching over my shoulder has gotten my wife infected with Teh BRD, and she now wants one of her own.:D

Chipperman
February 26, 2006, 10:11 AM
"If you get a Dissipator, strongly consider getting a M4-profile or fluted barrel. Everyone with an HBAR Dissy says that it's muzzle-heavy, but I got the M4-profile Dissy barrel from Bushmaster and it balances just great."

I have a HBAR Dissy and love it. It does not feel especially muzzle heavy to me-- but I also shoot a lof of heavy rifles, so any AR feels light to me.

lycanthrope
February 26, 2006, 11:06 AM
Get the 16" first.....but don't kid yourself......

You're going to buy a 20" down the line anyhow. You won't be able to help yourself.

(Get Both)

Seraph
February 26, 2006, 12:56 PM
I reviewed my post of 2:30AM and realized that I had rambled on without getting to my point, which was that I'm betting my $829 (including a Hogue grip, GG&G side sling adapter, and Specter sling) RRA carbine will compare quite well with anything offered by Colt. But anyway...
I have a HBAR Dissy and love it. It does not feel especially muzzle heavy to me-- but I also shoot a lof of heavy rifles, so any AR feels light to me.
Completely agree. I think there's a bit too much made over light profile barrels. You go with a pencil-thin barrel to save weight, then add a 10 or 12 oz free float tube (usually the quad-rail type, of course) to eliminate torquing that thin barrel, then you have to use every available inch of that quad-rail "real estate" to hang a pound or more of hardware from the forend of your rifle. All said, you only end up exceeding the weight of a less-laden HBAR carbine by maybe a little less than a pound.:rolleyes: I don't intend to dispute the usefulness of the quad rail forends at all, and I still find the hardware-laden carbines light, but, if I were looking to shed weight from a rifle, I'd probably have to ditch the flashlight and the kickstand before going with a thinner barrel. To me, the best advantage of the 16" carbines is that they are shorter.

Zach S
February 26, 2006, 01:11 PM
To me, the HBAR carbines balance something like the government profile rifles. I never really thought a plain jane, untacticool AR was front heavy until I picked up a HBAR rifle.

TacticalM4
February 28, 2006, 10:09 AM
For Fun shooting only, I would only recommend the 16"... I wouldn't want a 20" ever, I think you would regret getting anything over 16" unless you like the old M16 look. I'm actually thinking of going to a 14.5" Military spec M4 barrell..

The 16" seems a bit long for my carbine.. then again I do have the Superlight 16" Bushmaster barrell.

Correia
February 28, 2006, 11:10 AM
I'm going to get myself a midlength RRA out of this group buy, but I think I'm going to put a low profile gas block, and a rifle length float tube over it, for a mid-length dissipator. I've not owned a mid-length before, but I like the idea.

engineer151515
February 28, 2006, 11:17 AM
Of those two 16" I have, one is a M4 CAR profile. The other is a Bushmaster 16" HBAR configuration.

The HBAR is nose heavy relative to the CAR - barrel lengths being equal. Not ungainly though. The HBAR is suppose to perform better under sustained fire situations, handing the heat buildup better. But heat is probably not a concern to the average range shooter.

Alex45ACP
March 2, 2006, 09:05 PM
Speaking of which, how are you liking the Sabre rifle?

Haven't gotten to fire it yet :banghead: :rolleyes:

Moved to a new state and have been too busy, still have to get a lower receiver :evil:

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