16" or 20" ?

There's roughly 100 fps velocity difference between a 16" and a 20" barrel. All else being equal, the 16" barrel actually has a "potential" to be more accurate as it would be slightly stiffer... assuming you're using a scope and iron sight radius has no bearing.

The two guns you refer to have, at least in the specification, different barrels. One is 16" SS, while the other is "AISI 416R Triple Lapped, Stainless Steel, Match", and there is no specification on diameter, which I'd bet is larger on the 20" barrel... so they are not equal. Do they have a 16" or 18" barreled rifle with the same specs as the 20" rifle?

So... you need to do some additional homework.

20" ar10's border on too heavy. 16's are at least reasonably handy. However a 16 is likely shooting 150's at only 2550 where a 20" will be doing 2700 or better. If I were going to sling it and carry it a bunch no question I would get the std armalite carbine with a nice lightweight scope/ mount combo. But if I knew I were not going to carry much I would get the 20.

20, the muzzle blast on a 16 is horrendous.

I'd go with a 20" barrel for the added velocity and sight radius (I preferr iron sights) but not with the heavy profile that Armalite puts on their AR10T series. .875 under the gasblock is just too heavy.

Something like this: http://www.armalite.com/ItemForm.as...Category=f4bd4a13-55d1-41aa-aea0-49488ec48776

Then add this: http://www.midwestindustriesinc.com/index.cfm?fuseaction=category.display&category_ID=1118

The 20" seems to have the free floated handguard while I am not sure about the 16" but see no mention of it. My choice would be the 20" but that is a matter of your preference.

Ron

I had the 20" T model it was pretty much just a bench gun being so heavy. Now I have the carbine with pencil barrel and break. I like it a lot better, light weight and recoil, just have a eotech on it..

//All else being equal, the 16" barrel actually has a "potential" to be more accurate//

Until the projectile from 16" gun goes subsonic sooner

Stay with 5.56 if 16". 308, 20". I would not go less than 18" if 308.

I would go with the 20" for a 308... you likely are choosing a 308 over a 556 for its power, so it doesn't make much sense to me to leave cut the barrel short. A 20" gun is still pretty handy as long as you aren't getting in and out of vehicles.

If you were in the market what barrel length would you chose in a AR .308 platform 16" or 20"?

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That would really depend on what I wanted to use the gun for. For what you describe I would lean towards the 20" gun. I have 16" barreled 308s too.

20, the muzzle blast on a 16 is horrendous.

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I don't know that I would say that. I rather like shooting mine. Of course muzzle blast can differ significantly based on what is on the end of the gun. There is notable muzzle blast on a 16" 308 though.

I prefer the 20" length as well. Take a look at the ballistics tables for the bullet(s) you plan to shoot. That +-100 fps will mean a lot as you increase your target range (distance).

I tend not to co-mingle rifle types. If you want a close battle rifle then go a lesser round say 6.8 or 5.56. If you want a more open range rifle with legs then the 308 is a good basis to start with and accept the 20" tube. This is exactly what I did with my LR308 and a 20" barrel. Nothing wrong with 16" except for increase blast and it is a little lighter as others have pointed out.

I have two LR308 uppers with one being 16" and the other 20". Both barrels are free floated and shoot well. If you plan on shooting greater distances you will be better off with the longer barrel.

the most part it will be used for target shooting

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Get the 20". If you scope this rifle it well weigh in around 12+ lbs. It well be a very stable bench rifle with very moderate recoil. If you want man portable go with the 16" Infantry carbine.

I enjoy my 21" Noveske N6 more than anything I own. It's like shooting laser guided smart bullets.

Girodin,

Ever shoot one in low light?

"16" or 20" ?
If you were in the market what barrel length would you chose in a AR .308 platform 16" or 20"?

They claim to have the same accuracy out of both. The 16" comes with flash suppressor and forward assist. The 20" does not.....

So what factor's would make you chose what barrel length?"

Accuracy - Using iron sights, the distance between the two sights is important. Optics don't care. Length of barrel makes for more points of pressure to deal with. So the 16 inch has 4 inches less area for external influences.

Velocity/energy/trajectory - Higher velocity provides greater energy and a flatter trajectory. It's just the physics of it.
I don't have a 308/7.62 in 16 in or 20 in. But I have one with an 18.5 inch and one with a 22 inch barrel. With the same loads this is how they stack up:

FMJ 150 748 43 2468 Rem 600 11/13/11 18.5 inch 1 in 10 twist

FMJ 150 748 43 2677 M1A 11/13/11 22 inch 1 in 11 twist

Yes, I know this is a wimp load.
3 1/2 inches shorter or longer for 209FPS velocity difference. Not a great deal but on the range it makes a large difference.

The 16 in barrel has a flash suppressor, it needs it. 308/7.62s are not loaded with fast burring powders. Out of shorter barrels, lots of powder is burned after the bullet has exited. That makes for flash and concussion. And as for the forward assist, my opinion is, wow, lets pound that round in a little more and make sure it is stuck.

The 16 inch barrel is handy, more maneuverable and lighter. The 20 inch barrel will/can shoot farther/harder/flatter with less flash/concussion.

You have my views. You should gather as much information as you can, then make your selection using your needs and desires as a reference.