I am sure this has been covered, but I cant find it anywhere. What are the advantages of each?? I am trying to decide on a 14,5" with a perm. phantom attached or a 16" any pros and cons???

Someone mentioned Ammo Oracle in an earlier thread.

I went their myself to look up info on the 11.5" barrel.....There is a good comparison of ballistics based on the military 5.56 rounds and different barrel lengths.

It's eye-opening, and very interesting to say the least.

Hope that helps....It helped me.

Although I'm not 100% sure, I think bayonets will work on 14.5" barrels that are brought to 16"with a FS but will not work with 16" barrels with an FS attached. Dunno if you planned on getting a bayo but if that's a concern, there ya go.

If you want a bayonet mounted AR15, than go with a 14.5 with phantom or vortex.  I own a colt m4 14.5 and a colt M4 16.  You will not loose enough between 1.5 inches in speed if you ask me.  But than, I am no expert.  The advantage of the 14.5 is less weight and more manuevarabilty ( I know, mispelled) for CQ.

16 inch B/C unless you go NFA a 14.5 inch barrel will still end up being 16 inch, so you may as well get all the velo. you can.

Who cares about the bayo, and if you do, there are two solutions, there is a clamp on bayo lug that can be positioned accordingly, or there is an M7 bayo that has been stretched for the 16 inch barrel.

I think a dissy or midlength setup can also accomodate a bayo, but I'm not positive.

If you can have a threaded barrel, or when the ban expires and you can have a threaded barrel, you can change the muzzle device without machining it off.

Thanx for the info, I think I want one just so its as close to a M4 as I can get. Didnt even think about the bayonet, but I doubt I will use that.

What Stryfe said. Get all the velocity you can, its just an inch and a half right?

Tex78

is it legal to have a threaded barrel of any length? For some reason I thought this was illegal even if your barrel is 16" or longer.

Now a 14.5 with brake attached is legal right.   But it has to be welded or can it be pinned?


Before I checked the Bank account I was looking at the XM177 uppers from Model one.  They have the FS perminantly attached but is it a break or FS?

I say go 14.5 and permanently attatch a Vortex.  To me that just seems right.

Quoted: Now a 14.5 with brake attached is legal right.   But it has to be welded or can it be pinned? Before I checked the Bank account I was looking at the XM177 uppers from Model one.  They have the FS perminantly attached but is it a break or FS?

I don't think anyone mass produces a XM177 bbl that is post ban compliant, I think there was someone on the EE selling a kit though. Honestly, I'd wait it out.

Quoted: is it legal to have a threaded barrel of any length? For some reason I thought this was illegal even if your barrel is 16" or longer.

Post ban no.
Pre ban yes.
Or, if the ban sunsets in Sept, it will be open to all.

Depending on what the rifle will be used for and in what capacity will dictate barrel legnth.If you are looking for a personnel defense rifle any barrel legnth from 11.5,14.5 or 16" will do.What is true now was true 60 years ago 95 % of combat infantry engagements take place at 100 yds and alot of times under that.I think 50 yds is a more realistic range as soldiers and indeed armed citizens are only going to shoot at a threat they can see and if your being threatened in a life and death situation its probabaly going to be closer than 50 yds.On the other hand if you want a multi task weapon,something you can have capable of taking longer shots acurately then go 16".Try this site  www.isayeret.com the home page of the israeli special forces and see what types of barrel legnths they use for their purposes...it will surprise you,they use an 11.5 barrel as a 300 yd designated marksmens rifle as well as other barrel legnths.Me personaly I have all 3 simply because I didnt want to have the same AR as I own a few,I wanted them all to be a little different.If I had to go with 1 AR it would be my A2 Bushy pre-ban with 14.5/phantom HBAR with Aimpoint,M4 handguards,type 2 telestock and H buffer,thtas my babay out of them all.

Do like me!

Build one of each.

All I can share is my personal experience...

I had a Bushmaster 14.5" fluted barrel with permanently attached Phantom.  I sold it and bought a Rock River Arms chrome lined Mid-length 16" barrel.  It's a tad heavier, but I kept running into all sorts of issues with not being able to remove the flash supressor.  It's only 1" longer over all if you use an A2 FS on the 16".

In reality though, there was not one single bit of noticeable difference between my 14.5" and my buddy's 16" shooting side by side.  Accuracy was comparable, noise level, weight, etc.  The only way you might be able to tell which one fired a round was with a chronograph.  So I wouldn't let muzzle velocity influence my decision.

If you want an M4 clone, then I feel like 14.5" is the only way to go.  If you just want a carbine, then I think you'd be happier in the long run with a 16", and I always vote mid-length for those.