The "best" barrel length for AR

Building a 12.5" right now, possibly 10-11" if I cant find what I am looking for.. I am staying away from the 16"+ AR's since they are too close in size to the NR's that are 18.6" and I'd rather not have too many R's laying around. This way I have a shorter profile that doesn't spit hot flames (as much as say a 7 incher would), and have my NR for the longer shots.
 
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16", 1/8" mid-length, .223 Wylde. That's my all rounder. With a H buffer and a Smith Vortex, it's reliable, soft shooting and has virtually no flash.
 
Imo 14.5" or 16" mid-length or 18" rifle length. Anything less than 14.5 is fk'n annoying on the range. Do you care about velocity, wind drift and terminal velocity or are you going to carry it all day and never shoot it unless you're ambushed in a back alley? (Hey, nothing is worth doing if you don't looks cool doing it right?)

Moving on, the argument that 1/7 stabilizes better in cold weather holds some truth. It comes down to velocity from burn rate which changes with ammo temperature and can drop your barrel out of a node (or into one for that matter). As well, over-stabilizing a projectile can be an issue where bullets come apart from centrifugal force but It's really not with the reduced muzzle velocities from ar15's. If you had a 30 inch tube pushing 45 grainers at 4000 fps you would blow up some bullets. I don't see it happening with an AR though.

In conclusion, there are some great terminal ballistic charts out there but if you're shooting past 100 get an 18 or 20 inch. Less than that and get whatever looks the coolest. ��
 
9ineMM said:
After doing considerable research on the subject, I have still not not come to a conclusive answer. Many of you reading may ask "best length for what purpose?" A valid question of course. I am looking for not only objective points but subjective views. I have read all sorts of ballistic reports etc etc.

I guess a more accurate question is: "If you were to have only one AR15 for a multitude of purposes such as CQB to urban environments to extended environments and threats at 100+ yards, what barrel length would you choose?"
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On those criteria 14.5" barrel. Accurate enough and power enough out to 100 yards. The 14.5" is lighter and better balanced than a longer barrel and handles more quickly. Hence the reason the military has gone that way. If you want to go much past 100 yards then I think you need to look at a longer barrel. For 300 yards I would want a 20" barrel. With the longer barrel of course you start loosing the advantages of a 14.5 for close quarter or tight circumstances. As with everything in life there is no one size fits all but overall the 14.5" barrel is the most useful in my mind.
 
For play, I like the good-ol-fashion 20''

9ineMM said:
I guess a more accurate question is: "If you were to have only one AR15 for a multitude of purposes such as CQB to urban environments to extended environments and threats at 100+ yards, what barrel length would you choose?"
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For this kind of scenario, the "best" would be anything I can pickup on the battlefield...
 
14.5" seems (IMO) to be the best compromise between maneuverability/balance, velocity, and trying not to rupture your eardrums.

I suspect if Americans didn't generally need an NFA tax stamp to own an SBR, a lot of people would own 14.5's instead of 16's.
 
grinder08 said:
On those criteria 14.5" barrel. Accurate enough and power enough out to 100 yards. The 14.5" is lighter and better balanced than a longer barrel and handles more quickly. Hence the reason the military has gone that way. If you want to go much past 100 yards then I think you need to look at a longer barrel. For 300 yards I would want a 20" barrel. With the longer barrel of course you start loosing the advantages of a 14.5 for close quarter or tight circumstances. As with everything in life there is no one size fits all but overall the 14.5" barrel is the most useful in my mind.
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The US mil has adopted the SOCOM profile more because of politics than anything else. There is only about 3 oz difference between a 14.5" SOCOM and a 20" Government. While I don't have the numbers I'm almost positive that the C8A3 weighs more than a C7A2. Now if we start using more common sense profiles than I'd tend to agree but I'd hedge my bets with a 16".
 
grinder08 said:
On those criteria 14.5" barrel. Accurate enough and power enough out to 100 yards. The 14.5" is lighter and better balanced than a longer barrel and handles more quickly. Hence the reason the military has gone that way. If you want to go much past 100 yards then I think you need to look at a longer barrel. For 300 yards I would want a 20" barrel. With the longer barrel of course you start loosing the advantages of a 14.5 for close quarter or tight circumstances. As with everything in life there is no one size fits all but overall the 14.5" barrel is the most useful in my mind.
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This is complete BS. The velocity from a 14.5" gun is over 90% of that which a 20" barrel generates. The 16" barrel length gives you somewhere around 96% the velocity of a 20" gun. Read more and post less. As for the 100 yard comment you again are so far out of your lane it's disturbing. Having shot to 400 metres with a 10.5" gun with boringly consistent hits and using all lengths above that as well, I'm confident in the fact that you're information is regurgitated and not first hand. Regardless, there are plenty of discussions as well as videos online showing all barrel lengths making reliable hits well beyond 100 yards.... For giggles I sometimes shoot my pistols to 100 yards..
 
grinder08 said:
On those criteria 14.5" barrel. Accurate enough and power enough out to 100 yards. The 14.5" is lighter and better balanced than a longer barrel and handles more quickly. Hence the reason the military has gone that way. If you want to go much past 100 yards then I think you need to look at a longer barrel. For 300 yards I would want a 20" barrel. With the longer barrel of course you start loosing the advantages of a 14.5 for close quarter or tight circumstances. As with everything in life there is no one size fits all but overall the 14.5" barrel is the most useful in my mind.
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barrel6.jpg
 
Having run 7.5, 10.5, 14.5, 16 & 20 inch barrels my favourite is the 14.5 length because *I* find it has the best balance with my setups.
It suits *ME* best for cqb, three gun and targets out to 200 yds just fine.

YMMV
 
Kidd X said:
This is complete BS. The velocity from a 14.5" gun is over 90% of that which a 20" barrel generates. The 16" barrel length gives you somewhere around 96% the velocity of a 20" gun. Read more and post less. As for the 100 yard comment you again are so far out of your lane it's disturbing. Having shot to 400 metres with a 10.5" gun with boringly consistent hits and using all lengths above that as well, I'm confident in the fact that you're information is regurgitated and not first hand. Regardless, there are plenty of discussions as well as videos online showing all barrel lengths making reliable hits well beyond 100 yards.... For giggles I sometimes shoot my pistols to 100 yards..
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Don't agree with your comments in full.
Yes you are right the velocity drop between 14.5" and 20" is only about 10% or 300fps. Problem is when coupled with the 300fps drop in speed by 100m it drops the velocity below the generally accepted minimum effect velocity of 2500 fps for the 556. Doesn't mean you can't hit to a lot further but just ask the soldiers in Iraq and Afghanistan how effective it is past 100m. I personally believe that weapons need to fullfill their intended role and short of suppression fire an M4 is not really effective much past 100m. With the velocity drop with distance it is harder to hit at 300 with an 14.5" barrel than a 20". Now obviously you are a much better shot than the rest of us mortals so the increased difficulty of accurately aiming a short barrel rifle doesn't affect you but it does me. Now as I recollect the guy was asking what the best "one rifle does it all" is and I stand by the 14.5" It gives most of the benefits of both the longer and shorter barrels without compromising any one aspect too much. If you consider hitting a target at 400 yards with a terminal energy of less than 25% of the already pretty light muzzle energy (approximately the equivalent of a 9mm handgun round) is effective I guess you have a different standard to me. You can also hit a man sized target with a 22LR at 200 yards but I don't think many would call it effective.

Anyway I know I am wasting my breath on you Kidd X and I am fine with that, you can have your opinion and I will have mine just before you slag someone off make sure you are actually comparing apples to apples.
 
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I got a question...
Isn't it true that you shouldn't shoot steel targets within 50 yards with a 20 inch barrel due to the fact that it can put wholes thru the metal?
 
Boom_Stick said:
I got a question...
Isn't it true that you shouldn't shoot steel targets within 50 yards with a 20 inch barrel due to the fact that it can put wholes thru the metal?
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.....I'd be less worried about it punching through the plate, and more concerned with it coming back and kissing you.....
 
grinder08 said:
Don't agree with your comments in full.
Yes you are right the velocity drop between 14.5" and 20" is only about 10% or 300fps. Problem is when coupled with the 300fps drop in speed by 100m it drops the velocity below the generally accepted minimum effect velocity of 2500 fps for the 556. Doesn't mean you can't hit to a lot further but just ask the soldiers in Iraq and Afghanistan how effective it is past 100m. I personally believe that weapons need to fullfill their intended role and short of suppression fire an M4 is not really effective much past 100m. With the velocity drop with distance it is harder to hit at 300 with an 14.5" barrel than a 20". Now obviously you are a much better shot than the rest of us mortals so the increased difficulty of accurately aiming a short barrel rifle doesn't affect you but it does me. Now as I recollect the guy was asking what the best "one rifle does it all" is and I stand by the 14.5" It gives most of the benefits of both the longer and shorter barrels without compromising any one aspect too much. If you consider hitting a target at 400 yards with a terminal energy of less than 25% of the already pretty light muzzle energy (approximately the equivalent of a 9mm handgun round) is effective I guess you have a different standard to me. You can also hit a man sized target with a 22LR at 200 yards but I don't think many would call it effective.

Anyway I know I am wasting my breath on you Kidd X and I am fine with that, you can have your opinion and I will have mine just before you slag someone off make sure you are actually comparing apples to apples.
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The difference in drop between a 14.5 and a 20 at 300m with a 200m zeroing is 1/2MOA, and the total is 1.5 MOA out to 500m.

The fragmentation thing done by Frackler years ago was completely taken out of context. Hitting by a 62gr projectile in the vital or a major artery will kill you, fragmenting or not.

People who are shooting at anything beyond 100m and don't see immediate result most likely are experiencing a simple phenomenon- you MISS! I had a bunch of average "CAFSAC" shooters out shooting 10" white stationary targets from 100 to 250m in a field range using the prone position, it proves to be an ego bruiser for some who spend their entire career gauging their ability on PWT3 and CAFSAC, they were even given range time to zero at a square range before. Go to a live fire exercise and think of the rounds expended, and then take a look at the number of bullet holes in the targets. You will think that there should be at least couple hundreds of holes on them in a day. not.

And even back in the CAFSAC days when they still had 20" stationary Lockheed Martin ( and you can "cheat" this distance estimation by counting firing points from the backdrop) people avoid (or miss ) the 400m targets and anything over 250m is not a sure shot for most. This is still nice belly shooting on a nicely mowed firing point.

Your average soldiers exaggerate their shooting ability and they miss more than they know or will admit, especially out in the field.
 
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Boom_Stick said:
I got a question...
Isn't it true that you shouldn't shoot steel targets within 50 yards with a 20 inch barrel due to the fact that it can put wholes thru the metal?
Click to expand...

*MALICE* said:
.....I'd be less worried about it punching through the plate, and more concerned with it coming back and kissing you.....
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Steel targets? AR500 steel? Rounds from a 20" barrel aren't going to penetrate. Issue ball with the steel internal tip will leave little marks.

Malice's point about returns is valid.
 
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