Ar build 16" vs 18" barrel

[Bmcox86]

So I'm trying to decide on barrel length,  I'm building in 556 and plan on using it to coyote hunting and fun shoot. I am going to free float the barrel and am pretty sure I'm going with a 12" fore grip unless I can be talked into a 15"

What are the advantages of an 18" or a 16", any advantage on a 15 vs 12" foregrip

Thanks in advance

[Biggerhammer]

Hardly any difference. If you want to do it right, go 18" with a rifle length gas system, 13.5" or longer handguard. It's a 18" with the performance of a twenty. How wrong can the MK12 be. 

Can't wait for the "Google Foo" types to get all spun up on a rifle length 18".

[McCRIZZLEY]

I just got myself a dedicated dog gun. It's got a 16 inch barrel with a 13 inch hand guard. People will tell you 18's shoot better, but are harder to wield in the woods. 16's are "less accurate" but more maneuverable. I honestly don't think there is enough merit or difference to either argument to warrant any stress. I like the look of the 18's but would rather a bit more ease when hiking, as I enjoy doing a bit of that 

I think you will be fine with whatever you do.

[mountainman]

I just got myself a dedicated dog gun. It's got a 16 inch barrel with a 13 inch hand guard. People will tell you 18's shoot better, but are harder to wield in the woods. 16's are "less accurate" but more maneuverable. I honestly don't think there is enough merit or difference to either argument to warrant any stress. I like the look of the 18's but would rather a bit more ease when hiking, as I enjoy doing a bit of that 

I think you will be fine with whatever you do.

[McCRIZZLEY]

Some more food for thought...

So I have the 16". My buddy has a 20" and a 12.5" with suuuuper flash hider on the end. After finding ammo the guns like, we shoot groupings nearly identical. The only one that lacks a bit is the 12.5, but it is not free floating, and has cheap glass on it. However, while the groupings are similar, I have a lightweight barrel on my gun, and he has heavy barrel on his 20", the weight is drastically different. you can easily notice just lifting them. I would say the length isn't as big of an issue as the weight.

I'm sure some other guys with more experience will chime in though.

Long story short, don't sweat it.

And the longer foregrip is sexy. Do it!!!

[NaturalSelection]

Hardly any difference. If you want to do it right, go 18" with a rifle length gas system, 13.5" or longer handguard. It's a 18" with the performance of a twenty. How wrong can the MK12 be. 

Can't wait for the "Google Foo" types to get all spun up on a rifle length 18".

  I went 18" rifle length and the gun shoots very well.

[Bofire]

  I HAD A 16,  WHAT? I like 20.
Carl

[mountainman]

Some more food for thought...

So I have the 16". My buddy has a 20" and a 12.5" with suuuuper flash hider on the end. After finding ammo the guns like, we shoot groupings nearly identical. The only one that lacks a bit is the 12.5, but it is not free floating, and has cheap glass on it. However, while the groupings are similar, I have a lightweight barrel on my gun, and he has heavy barrel on his 20", the weight is drastically different. you can easily notice just lifting them. I would say the length isn't as big of an issue as the weight.

I'm sure some other guys with more experience will chime in though.

Long story short, don't sweat it.

And the longer foregrip is sexy. Do it!!!

you will find that what works best for you, what feels best to you, what shoots best for you, is what you should go with!  here on the internet, you will get some pros response, you will get some internet guru responses, some will come up with fact, some google and report as knowledgable, talk "Smack"  , without proof to back it up...
 Trust those who can back up what they claim. But again, a firearm is a very personal thing, so go with what feels best and shoots best! My 

[Jim the Plumber]

If you are going to run a can, my experience is run the 16" with mid length gas.  No can, go 16" carbine gas, of 18" mid length gas.
This is my recommendation after shooting well over 100,000  rounds through AR-15/ M16 platforms.

[carpsniperg2]

I prefer a 18" barrel myself.

[thinkingman]

I had an 18" bull free-float and it shot great.
I was really heavy and that probably helped it on the bench or bipod.
I traded for a 16" HB, and it shoots the same, but carries (and if you need to swing on a dog coming in fast)much better.
Barrel quality, chamber, muzzle(try to avoid 'gotta have tacticool!' FH or brake) and twist are going to have more influence than the length.
Also, the latest trend to have collapsible buttstock and picatinny EVERYTHING is not helping accuracy at all.
These are firearms, not Legos.

[Heredoggydoggy]

I have 16" barrels and 20" barrels on my ARs, and can tell very little difference in weight.  My lightest AR is the 450 Bushmaster.  That big hole in the barrel takes off a lot of weight!    With a low-profile gas block, you can use any length forearm you want.  A forearm that hides most of the barrel looks sexy! 

[slm9s]

in my opinion the 18 is the best compromise between portability and muzzle noise.

[huntnphool]

You might consider the twist rate as well as the length.

[Biggerhammer]

A 7 twist will cover it all  , 8's are great  and 9's. Well, you can have the 9's.

[jay.sharkbait]

I find these threads fascinating

[carpsniperg2]

1:8 and a 18" barrel is my favorite in a 5.56.

[WoodlandShooter]

some food for thought...IMO, it more of a personal preference regarding the difference between a 16 and a 18....they are both good for shooting R.A.T.s

[mountainman]

I find these threads fascinating

Always gets entertaining!

[WoodlandShooter]

Hardly any difference. If you want to do it right, go 18" with a rifle length gas system, 13.5" or longer handguard. It's a 18" with the performance of a twenty. How wrong can the MK12 be. 

Can't wait for the "Google Foo" types to get all spun up on a rifle length 18".

LOL, my father in law picked a MK12 barrel...had no clue what he had...said it would short stroke "slightly" and not lock back the BCG after the last round...anywho, I told him to run heavier loads that the 50 grain 223 stuff.

[Heredoggydoggy]

Hardly any difference. If you want to do it right, go 18" with a rifle length gas system, 13.5" or longer handguard. It's a 18" with the performance of a twenty. How wrong can the MK12 be. 

Can't wait for the "Google Foo" types to get all spun up on a rifle length 18".

LOL, my father in law picked a MK12 barrel...had no clue what he had...said it would short stroke "slightly" and not lock back the BCG after the last round...anywho, I told him to run heavier loads that the 50 grain 223 stuff.

Also, tell him to look at the gas rings on the bolt and make sure the gaps in the rings are alternated on the bolt.  I've shot 50 grain bullets in my AR, and they function fine.  Admittedly, they were handloads, but even at the bottom of the load range, they still functioned... 

[WoodlandShooter]

will do!!!

Iam just itchin to get my recce all put together...should have the remainig parts next week.

[ML_Hunter]

I'm not going to say much that everyone else hasn't said, but its going to come down to what you want. I built an 18" rifle for myself and a 16" for my old lady. As I shoot them, they are so close to the same and you really wont be able to tell at all the difference in how thy shoot. I do prefer a mid length gas system and the longer fore end. The 1/7" twist is a nice when you start shooting your 72+ grain bullets, but if your only shooting 55 or 62 grain bullets, all of the barrel twist rates will work just fine.

Have fun with the build , its quite fun and I'm sure after your first, you will be looking for an excuse to build more AR's 

[Bmcox86]

I went and checked some guns out today, decided to go with 18" barrel and 15" rail. The twist will be 1:7 and its a rainier arms mountain series.

[CastleRocker]

I went and checked some guns out today, decided to go with 18" barrel and 15" rail. The twist will be 1:7 and its a rainier arms mountain series.

Great choices.  The only AR's I've had that were pretty much the same (for comparisons sake), were the three R-15's I had.  The only difference between them were the barrel lengths.  I had a 16", and 18" and a 20".  The 16" is LOUD compared to the other two.  Other than the noise and the weight, I could never find a difference worth discussing.   

Still have the 16" and the 18".  Got into other caliber AR's and had to part with the 20". 

In my opinion, a flash hider/muzzle break is NOT a necessity, especially on a 223 or smaller, and will only help to destroy your hearing.  My DTech in 25 WSSM is my only upper with one, and the ports are very small, so it's not obnoxiously loud. 

[Biggerhammer]

I went and checked some guns out today, decided to go with 18" barrel and 15" rail. The twist will be 1:7 and its a rainier arms mountain series.

Well done, great choice.

[Craig]

18" barrel with 16.7" Noveske NSR rail. Great combo.