Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login
Site Notices
Posted: 10/14/2004 7:37:19 PM EST
As far as terminal velocity and accuracy, what do you stand to gain by using a 20" over a 16" barrell, is there much of a difference? Does a heavy barrell have any advantages over an M4 style barrell in this situation as far as the 16" is concerned?
Link Posted: 10/14/2004 8:51:57 PM EST
[Last Edit: 10/14/2004 9:03:05 PM EST by TexanInOhio4]

Originally Posted By azjeeper:
As far as terminal velocity and accuracy, what do you stand to gain by using a 20" over a 16" barrell, is there much of a difference? Does a heavy barrell have any advantages over an M4 style barrell in this situation as far as the 16" is concerned?



From what I have gathered over the last few months of reading many posts here, there will be hardly any difference in accuracy between those two barrel lengths. With the extra four inches of barrel length in the 20" you do get a velocity increase of several hundred FPS. That will push the terminal effects out to a greater distance. Consult the Ammo-Oracle to learn everything you could ever imagine about .223/5.56 ammunition, and how barrel length is a factor.

As far as the style of barrel....I think it's preference. Personally, I like a heavy barrel. Heavy barrels have the potential of being more accurate, which is why you see most varmint rifles with them.

Mike
Link Posted: 10/15/2004 6:57:28 AM EST
[Last Edit: 10/15/2004 6:58:21 AM EST by Jasoncap]
Barrel length in and of itself does not effect accuracy, but it does have a pretty big impact on velocity. I split the difference and went with an 18" barrel as a good compromise. Regarding heavy contoured barrels vs. lighter contoured barrels, there does tend to be greater accuracy potential, especially over longer sustained periods of fire. Heavier barrels will dissipate heat better which tends to keep your POI from "walking" as a barrel heats up. Please keep in mind that these are very general statements that do not take things like ammo type, barrel harmonics, atmospheric conditions, etc, etc, etc. into consideration. The main disadvantage (as I see it) to a heavy barrel, especially as you add length, is that they are, well, heavy. Depending on the type of shooting you do, that may not be a problem, though.
Link Posted: 10/15/2004 7:27:33 AM EST
The differences are 100 FPS, weight, and of course ergonomics. Amazing that the .223 only gains 25 fps an inch from 16 - 20 inches, but that is the case. The 6.8 SPC gains even less.

A heavy barrel takes longer to heat and shoots more accurately when hot -- definitely all good if you don't mind the additional weight.

Link Posted: 10/17/2004 3:49:07 PM EST
Less muzzle blast? I've never shot a 20", but the blast off my 16" is wicked.



Originally Posted By azjeeper:
As far as terminal velocity and accuracy, what do you stand to gain by using a 20" over a 16" barrell, is there much of a difference? Does a heavy barrell have any advantages over an M4 style barrell in this situation as far as the 16" is concerned?

Link Posted: 10/17/2004 4:15:59 PM EST
Thanks for the info. I was just wondering how significant the added velocity would be from a 16" barrel vs a 14'5"? Not a whole heck of a lot I guess. And accuracy would be about the same for targets at 200 yards or less?
Link Posted: 10/17/2004 4:17:27 PM EST
I meant 14.5"!!
Link Posted: 10/17/2004 4:27:54 PM EST
You need to get both , just to see for yourself
Link Posted: 10/17/2004 8:57:03 PM EST
yep.....just what I was thinking!
Link Posted: 10/17/2004 9:01:35 PM EST
a 14.5in bbl will loose up to 200+fps vs a 16on bbl

thats a lot to loose; accuracy also suffers after 100yrds in a 14.5bbl

go w/ a 16in min.



Link Posted: 10/17/2004 9:35:51 PM EST

accuracy also suffers after 100yrds in a 14.5bbl


Mine never did... Mine was good out to 360 yards hanging with the 16"s just fine.

There is no reason why that would be the case... Must have been an odd barrel you had there.

Link Posted: 10/17/2004 10:21:00 PM EST
hmmmm....

got to check on that again
Link Posted: 10/17/2004 10:24:22 PM EST
Link Posted: 10/17/2004 10:42:27 PM EST
[Last Edit: 10/17/2004 10:47:02 PM EST by topgunpilot20]

Originally Posted By ALPHAGHOST:
a 14.5in bbl will loose up to 200+fps vs a 16on bbl

thats a lot to loose; accuracy also suffers after 100yrds in a 14.5bbl

go w/ a 16in min.




it's closer to a 80 fps loss.

straight from bushmaster:
Link Posted: 10/18/2004 4:51:55 AM EST
The interesting thing is that while you gain about 80 FPS in the 1.5 inches from 14.5 to 16, you also only gain about 80 in the 4 inches from 16 to 20. For me, that makes 16 inches just about ideal.
Link Posted: 10/18/2004 6:02:43 AM EST
[Last Edit: 10/18/2004 6:13:52 AM EST by model927]
Not to offend any one but terminal velocity,accuracy all this stuff about barrel legnths is meaningless in an AR used for self deffense although ARs are exceptionaly accurate for self loaders,let me explain.As is true for the last 60 years real world distances that we would have to use said weapons in self deffense 95% of the time is under 100 yds and 75% of that time well under 50.Now depending on where you live that can be different.I live in the city and am not far from woods and mountains so I use tha shortest legaly possible on my ARs 1 11.5/5.5 and 2 14.5 HBARS 1 1/7 the other 1/9.All these legnths are ideal for ranges under 100 yds the range at wich most engagments take place.If I lived in a more open area where I might most likely have to take longer shots then I would use my 20" AR or my M14 type of rifle.Accuracy wise my 11.5 is most effective and accurate under 50 yds and the 14.5 barrels will give same accuracy as a 20" out to around 350 yds.So a 14.5 is plenty.Fragmentation on the other hand for a 14.5 is under 100yds about 130 to 140 for a 16" and 200 and unbder for 20".Under 100 is fine with me as the 14.5 fills the bill for me according to all the other factors most importantly geographic location and living area and space.I think though most of the time a 14.5 and even 11.5 will fill the bill for a self defense AR.I like and have a 20" also but its my CMP rifle as I like things small and compact for all around use.So 20" vs 16" I beleive 14.5 is best unless you need something more effective at longer distances.I beleive 16" is irelevant because you could just go shorter to 14.5 and not lose much velocity because if you have a carbine your expecting to fight in the ranges a 14.5 will handle just as well.I like my 11.5 but it has to have a permanent 5.5 and I might as well use the extra legnth for barrel I just dont hold that out look with a 16 vs 14.5.If I wanted a 16 for extra range I might as well go 20".If space is not at a premium and you need something to shoot farther go 20" or even .308.Most soldiers only shoot at what they can see and thats more often than not at ranges well under 100 yds.In the end its a matter of need a little want and what your itended purposes are for your rifle.When you know what your gonna use it for it will narrow things down for you and you wont have to worry about wich is best.Me Im screwed because I like carbines for defense and carrying but Im a die hard AR fan and like to collect so I have other barrel legnths and in some cases just barrels,in the end its your choice just think what your needs are before your wants when it comes to a defnsive AR,the rest of the time "wants" will do fine.The most relevant thing about velocity is what distance what ever barrel legnth you use you will be able to maintain 2700 FPS to have the best chance for the bullet to fragment wich even at the proper ranges can be iffy because people come in all shapes and sizes.What may deform in one body may not do in another even at the same distance with the same weapon.
Top Top