Need Help Building an AR15

[jdougg92]

i have started working on the upper half of my AR. The upper and lower receivers are from my Bushmaster ORC, with skeleton stock, and dynamic 3 trigger.

I don't know if it was photo shopped or not but I saw a picture of an AR15 SBR where the hand guard and suppressor(& barrel) were even at the end. I thought it was awesome and want to do the same thing but only go big. I found a few 24" & 26" barrels...

But does any one know where I can find hand guards of equal length. I'm having a hard time finding anything over 14"
Also are there any issues with having equal length barrels and hand guards?
Also (I've never taken down an upper), are the ports for the gas tube universally the same distance from the receiver no matter the barrel length or does it just depend who makes it?

 

[HOOfan_1]

The gas tube length depends on the specific gas system

Pistol/carbine/mid-length/rifle

Barrels over 20" are fairly rare on AR-15s. I doubt you are going to find any handguards over 15".

 

[Sam1911]

The gas port location in the barrel is dependent on the length. The most important aspect is to have the right amount of barrel AFTER the port, as well as setting the port diameter to work with the barrel length properly.

The chocies here are most "pistol," "carbine," "mid-length," and "rifle." (Here's a picture over on CalGuns that shows some of the common choices: http://farm7.static.flickr.com/6055/6284852777_6959712be8.jpg)

As far as the free floating tubes/handguards go, the longest I've seen is about 15.75", with 15" being the longest common one.

There aren't any issues with having them longer than that, except maybe eventually getting so long that there's too much stress on the receiver and nut. The makers don't do it because there isn't any point. 15" is about as far out as you're going to reach, or be able to reach, so making one as long as a 20" barrel (and certainly longer) is useless.

While most folks do consider "looks" when building a rifle, there still remains some element of practicality to the choices offered most of the time. A handguard 6-10" longer than you could ever reach out and put your hand on is sort of "clown shoes".

 

[wally]

Also are there any issues with having equal length barrels and hand guards?

Only if you get your fingers in front of the hand guard and thus in front of the barrel. Definitely something you have to worry about with an SBR. I have a fake suppressor I put inside my hand guard when the real one is on a different gun so that hands and fingers don't get blasted if gripped in front of where the 5.5" barrel ends.

 

[gazpacho]

On SBRs, the effect you describe us usually created with the suppressor installed inside a free floated hand-guard (as mentioned above). At the extreme length you desire makes that difficult, mainly, as no one makes a free float hand-guard that long, AFAIK. Also, at that length, lighter barrels will exhibit more "barrel whip" than heavy and/or fluted barrels, adversely affecting accuracy.

As mentioned above, a longer free float hand-guard will put more stress on the upper receiver/barrel nut. Think of the guard like a lever. The longer it is, the more force it can assert. If you are going mainly for looks, you could custom attach the hand-guard to the gas block. I would use easy to source plain carbon fiber tube. Or you could go with a custom aluminum guard. Either way, the result is going to be VERY front heavy.

I can understand your desire for a longer look. A few years back I ordered a 24" heavy barrel A2 1in7 upper from Model 1 Sales. At the chrono, it exhibit a very modest increase in velocity. Since I went with an A2 upper, I shoot it with iron sights, mostly for plinking. I wanted an AR-15 Rifle not an AR-15 Carbine.

Good luck with your build. The great think about ARs is that you CAN make funky builds without ruining your firearm.

 

[MachIVshooter]

Longest handguard I'm aware of is 17.5"

http://parallaxtactical.com/product...15-free-float-super-slim-rail-ffssr-backorder

As mentioned, the .223 doesn't gain much after 20"-22" of barrel, especially with factory ammo and lighter bullets. I settled on a 22" to fire handloaded 75 and 77 gr match bullets, and I use slower powders to take advantage of the length. With 55 or 62 gr. ball, there is basically no increase in velocity over the 20".

For the look you desire, that Parallax handguard with an 18" barrel (or 16" with a long linear comp) is gonna be the way to go.

Personally, I find the appearance of a 16" barrel with a 15" hand guard appealing. I have one build done that way:



My 22" bull also sports a 15" handguard, which I think is a decent look:

 

[QwikKotaTx]

LaRue makes a very nice handguard but it's only 13" and pricey.