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The Annoyed Man wrote:

Bitter Clinger wrote:

locke_n_load wrote:

hounddog wrote:I'd like to ask a quick question if you all don't mind? I'm not real saavy on barrel twist rates. For a 5.56 barrel of 16" length, what do you think is the best twist rate? I've heard some are better for different things and I see they offer 1-7, 1-8, and 1-9. Excuse the limited knowledge I have on this please. I'm more familiar with pistols.

Stay away from 1-9 if you can, as it will not stabilize heavy bullets, if you ever plan on shooting any. 1-7 is most common after that, and then 1-8 is somewhat rare, but both should be fine. If you plan on shooting very light bullets (<50 gr) and very heavy bullets (>65 gr), go with a 1-8.
But if all your shooting is 55-62 gr (most common ammo), either of the 3 will work for your purposes, but I personally go for 1-7.

http://texaschlforum.com/viewtopic.php? ... e&start=15

Yep. My last two builds have been on 1:8 barrels.

Another hint.... Generally speaking, comparing any two barrels of equal length in which one has standard rifling and the other has some form of polygonal rifling, the polygonal rifling will tend to produce slightly higher velocities without negatively affecting accuracy. Just like other smaller calibers, .223/5.56 bullets tend to rely on high velocity for wounding potential, particularly with ball Ammo, and carbine length barrels produce lower velocities than than mid or rifle length barrels. Polygonal rifled barrels tend to cost more than their standard rifled counterparts, but not necessarily tons more. In my opinion, it is well worth the bump in cost for a polygonal rifled barrel, especially for a carbine or SBR length barrel, to bump up muzzle velocities without raising chamber pressures. And, there is an additional benefit, and that is that polygonal rifling is MUCH easier to clean, as anybody who owns both a Glock and a 1911 can tell you.

1:8 seems to be the best all around. It probably won't shoot the heavier bullets as well as a 1:7 or the lighter as well as a 1:9 but it will shoot the midweights great and shoot lights and heavies pretty well. I know TAM will agree with me on a quality barrel being the backbone of your gun!

parabelum wrote:Honestly, if this is your first AR I would highly recommend getting a factory built AR, 5.56 chambered with 1:7 twist and first get familiar with the basic in/outs, construction etc.

I respectfully disagree, I think that building one is the best way to learn the ins and outs of the rifle. With a vise, upper and lower vice blocks, an armorers wrench, and a razor blade you can put together a very nice rifle. As far as getting everything to shoot straight, to me that completely is subjective to the barrel of your choice. You could buy a $400 match grade shihlen and have problems like headspacing, but you will find that the cheaper barrels will definitely have flaws far more often than the expensive ones. How the user installs the barrel can affect accuracy but typically if correctly installed (not hard at all) a more expensive well known match grade barrel is what it is. My point being accuracy is about the barrel and free floating rather than specific torques or installing one way or another. As long as your barrel is tight, your gas system is true and all holes properly lined up, there is not very much more that the end user can do to make it any more safer than a store bought gun. The headspace obviously "should" be checked but once again a quality barrel should eliminate that. But then again I love building things and take pride in saying that I put my rifle(s) together myself.

The vice is pretty necessary. The torque wrench- eh some people are going to tell you yes, some aren't. I'm a fairly large guy and when I tighten barrel nuts I get it about as tight as I want it (which is pretty tight, but not break threads tight) and then match the next hole in line for the buffer tube. That process hasn't let me down yet. That being said I haven't put anything super expensive together either. If I was putting some pricy parts in a noveske matching receiver set with a real nice barrel I might torque it.

If you can build a lego set, you can put together an ar! Buy an assembled upper receiver (just dust cover and f/a) to save a little time for just a few dollars more. Use a quality bcg and barrel and you should be happy with whatever you chose! Like stated above no fancy tools required besides armorers wrench and vice blocks