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Posted: 4/5/2015 10:47:44 AM EDT
| I'm looking to build another AR 15, I wanted to know some opinions on a 16", 18", and a 20" barrel is there that big of a difference? |
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If you handload you can take advantage of longer barrel length. Slow burning powders with heavy bullets (like the various 75+ grain bullets) and fast twists benefit from longer lengths if you want to stretch the distance. All of the prairie dog rifles I've built have been 24", and there are some surprised 'dogs at 600 plus yards. Could the same thing be achieved with a 16-18-20" barrel. I suppose.
Edit: well hail......I forgot to say that my P-doggin rifles are all done up in .223AI. Couple extra grains of slow burning powder makes a difference. Da! |
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With my pet load, I loose 50 FPS going from a 20 inch barrel to a 16 inch barrel.
Varget 75 HDY HPBT Maybe once you start getting in to like 24 inches , you start to see some real improvement. For my load I don't see any reason to run anything greater then a 16, with the suppressor that brings total length to 22. |
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The difference is splitting hairs, but less wind drift and less bullet drop are always desirable. I personally really like my 18 and how it feels when compensated. Muzzle is flat with a recoil burp. My 16 inch was also smooth, but not as smooth as the 18.
I'm in the higher velocity camp. The more the merrier. |
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A well made 16" barrel can be more accurate than a run of the mill 20" barrel. Go with a reputable vendor and reputable barrel maker.
Depending on what you're after, a 16" barrel could be just the thing for you. Or a 20" barrel might be better, depending on what you're going to do with the rifle. I have one 20" rifle, and it's configured as an M16A4 clone, so it has that barrel. Most of my others have 16" barrels (except the one with the M4 upper). Keep in mind that the Army considers the M4 Carbine (with a 14.5" barrel) to have a maximum effective range of 500 meters for point targets. That's almost 550 yards. The Army's stated maximum effective range for point targets with the M16A2 is only 550 meters (about 600 yards). That's a 5 1/2" barrel length difference for only 50 more meters effective range. Go with a barrel length that suits what you want, and don't worry too much about the other stuff. |
| The difference is drift, and drop. But even a 16 inch is good for 600m. You just have to aim higher because your bullet will have a much higher arc due to the lower velocity. Either way the bullet will still have more than enough power at 600m to kill a lot of stuff! |
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Speaking of 5.56/.223, out of those 3, get the 20". Get all of the velocity you can. I would also recommend a heavy barrel. No need for bull, if you get a decent quality.
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If you handload you can take advantage of longer barrel length. Slow burning powders with heavy bullets (like the various 75+ grain bullets) and fast twists benefit from longer lengths if you want to stretch the distance. All of the prairie dog rifles I've built have been 24", and there are some surprised 'dogs at 600 plus yards. Could the same thing be achieved with a 16-18-20" barrel. I suppose. snip.... this is spot on. |
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At what distance do your bullets go subsonic? Quoted:
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Go SBR 11.5 inches and never look back. At what distance do your bullets go subsonic? If he is trying to shoot at a distance, why choose a platform that makes shooting at a distance more difficult? The key is anyone can take a 11.5, 7.5, 16, or 20 inch barrel and punch in the numbers in a ballistic calculator and suddenly you have your dope. Suddenly a 10.5 is a super good all around gun for CQB and its also a pocket sniper rifle... But if you are shooting at a target, say a prairie dog as noted above...you want a bullet flying as flat as possible to mitigate errors in range calculation. A mobile target puts you under duress of time. If you lob 77 grainers at 400 or 500 yards from your SBR at our imaginary prairie dog then your dope has to be spot on, where as the flatter trajectory of the long guns permits your bullet to hang in the verticle space occupied by your target for a longer length of distance. We didn't even mention wind. With a flat shooting gun you have less clicks to get your impact point where you want it, where as with something thats more of an arched trajectory needs more adjustment to get on target. If your trying estimate a shot, I would rather have the trajectory more forgiving of error. But its really splitting hairs unless we talk about differences in barrel length greater than the 16-20 inch range. Edited for clarity. |
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