Bull Barrel length for a .223 AR


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White.01
February 20, 2009, 01:58 AM
So I admit to be a newb to this site, I searched and couldn't find an answer.

My question: What is the best barrel length for a .223 AR? I hear that a 24" barrel may add some stability and also lessen the report of the rifle. I've been leaning towards a 20" DPMS flattop.

However, I remember reading (don't remember where) that any barrel length over 16" on a .22 is counter-productive. The idea was that all of the powder and thus velocity was maximized/used up at around the 16" mark of the barrel, so any further travel in the barrel, past 16" would actually slow the bullet down. Also, after a day of plinking, residue would build up around the 16" mark and impact the accuracy as the bullet would hit a "constriction" in the barrel.

Now just because I read it doesn't make it true, but it sounds logical. Velocity can't increase forever in a barrel.

Thoughts?

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Beagle-zebub
February 20, 2009, 02:31 AM
However, I remember reading (don't remember where) that any barrel length over 16" on a .22 is counter-productive. The idea was that all of the powder and thus velocity was maximized/used up at around the 16" mark of the barrel, so any further travel in the barrel, past 16" would actually slow the bullet down. Also, after a day of plinking, residue would build up around the 16" mark and impact the accuracy as the bullet would hit a "constriction" in the barrel.

That information is only true for the .22LR rimfire cartridge. Centerfire .22 cartridges still pick up velocity with more barrel length--with the .223, this is true at least up to 26" of barrel. The part about a "constriction," I can't comment on.

Interceptor_Knight
February 20, 2009, 02:37 AM
A 20" AR is a nice compromise. High Power shooters are hitting targets at 1000M with a 20" barrel. You normally see 24" barrels on the varmint rigs where they are doing all of their shooting from a rest.
There is nothing magic about the 16" mark on a .223 barrel which would cause additional fouling...

rangerruck
February 20, 2009, 05:10 AM
In all reality, you will get about all the speed you need with a 22 inch bbl.
the only diff needed to know really, is how heavy a grain weight bullet are you shooting? the heavier/longer the bullet is, the faster twist you will need. I like a 1/8 twist, good from 45 all the way up to about 75 grain bullets.

rangerruck
February 20, 2009, 05:11 AM
Beagle was right as well, a 16 inch bbl is all you need on a 22lr.

sourdough44
February 20, 2009, 07:56 AM
Much depends on what you plan to do with it. Even a 16" 'Bull' barrel can be heavy to carry around. I have(or had) AR's in 16,20, & 22". For ease of carry you can't beat a lighter weight 16". If I saw a Bull 16" I think I'd rather put some of that weight into a longer barrel. A 24" can be heavy & unwieldly to carry at the same time.

moooose102
February 20, 2009, 09:01 AM
the only problem i see with a long bull barrel is weight. someone should make a 24" fluted titanium chrome lined bull barrel for these! of course they would be $800.00. but somebody would pay for it. not me, but many people have "cubic dollars"!

Dr. Tad Hussein Winslow
February 20, 2009, 11:47 AM
I'd go with 22" if unfluted, or 24" if fluted.

MotorOilMcCall
February 20, 2009, 12:35 PM
I went with a 20" unfluted...

usmc1371
February 20, 2009, 01:01 PM
I have a 26" on my 204 and it weighs a ton and sucks to shoot offhand the balance pretty much sucks. If I could have gotten a flutted one I would have. In 223 I am looking for 16" maybe 20" but someting that swings easy and doesn't weigh 11 pounds

Rembrandt
February 20, 2009, 01:14 PM
Went with a DPMS 24" fluted bull barrel.....superb accuracy, my other shorter barreled AR's don't come close to doing as well.

http://img.photobucket.com/albums/v405/Rembrandt51/ar-1.jpg

Jim Watson
February 20, 2009, 01:17 PM
What is the rifle to be FOR?
My Long Range AR has a 28" barrel, but it is shot strictly off a bipod in F-Class.
The Army got along for years with a 20" barrel and if you mean to carry it around or shoot it offhand much, there is no reason to do anything different.

ForneyRider
February 20, 2009, 03:47 PM
I have the DPMS panther bull 20. It is heavy, but very accurate.
If you plan on doing any hunting that requires walking/hiking, I'd get the HBAR.
I have 1:9 twist. I think 1:8 is more common with the Rock River or Bushy.

lej
February 20, 2009, 08:58 PM
My question: What is the best barrel length for a .223 AR? I hear that a 24" barrel may add some stability and also lessen the report of the rifle. I've been leaning towards a 20" DPMS flattop.
--------------------------------------------

I guess before you can truly answer this question then you need to ask yourself , what role did you want your rifle to perform.

The .223's wound mechanism is largely fragmentation, once you drop below a certain velocity (depends on the bullet) the bullet will no longer reliably fragment and as such you will not create much of a wound cavity making it less effective. Off the top of my head i think its around the 2200fps mark but i could be wrong (having a bit of a mental blank at the moment). Basically the more velocity you start with the greater the fragmentation range you have. And thats where we get back to the original question what do you want to do with the rifle? An AR15 with a 10.5 inch barrel may generate lets say 2450fps at the muzzle, by the time it reaches 100 yards the round has dropped below 2200fps and it fragmentation threshold thus making it effective at distances under 100 yards. This is the trade off that swat and tactical teams make with short barrelled carbines, they are easier to use inside a house because of there compact size but are lacking as a field rifle.
On the other hand firing the same .223 round out of a 24 inch barrel may give you a muzzle velocity of say 2900fps, at 100 yards it is still doing 2700 fps, at 200 yards it is at 2490 and doesn’t drop below 2200fps until it reaches 275 yards. Having said this I have a bushmaster with a 24in barrel and its not the sort of rifle in would prefer to be using for home defence or dragging through thick undergrowth if I didn’t have to. Its negative point is size, length and weight.
Like all rounds the .223 will have an optimum barrel length I would think it would be somewhere round the 26/ 28 inch mark before friction in the barrel will slow the round down prior to exit (having said that ive never seen a .223 with 28 inch barrel). Jumps in velocity between 10-12, 12-14 and 14-16 inches are quite significant, ie for arguments sake say 120fps (for 2 inches). from 16 inch onwards the improvement in velocity with barrel length in less pronounced i.e. the jump from 16-20 may be 100 fps and the jump from 20 to 24 maybe 70 fps and gets less as barrel length progresses.
I would think that probably the most popular barrel length these days is the 16 incher, it sort of a trade between portability/ handling and round effectiveness.
Practically if you want a rifle solely for home defence get a short barrelled one, shooting people at 10 yards you do not need a 275 yard fragmentation range, if you want a rifle for long range varminting get a 24 incher because you'll be shooting off a bag or a bipod where every fps counts with extended range and flatter trajectory, if you want an all rounder find something you like between 16- 20 inches.

As for stability shouldn’t have much to do with barrel length and you wont get much difference if any at all in the report between 20 –24 inches

All the above figures and velocities i just pulled out of thin air for the purpose of explaining my points so please dont hang me on there accuracy, but you get the idea :)

Interceptor_Knight
February 20, 2009, 11:09 PM
The .223's wound mechanism is largely fragmentation
Maybe if you are using FMJ, but not hunting rounds. I use hunting rounds for deer and defense loads. I do not rely on fragmentation. A 60 gr Nosler or a 64 gr Power Point on bigger game and V-Max type bullets on the smaller stuff.

benEzra
February 21, 2009, 12:25 AM
Maybe if you are using FMJ
Or lightweight JHP's (40-55 grain).

jpwilly
February 21, 2009, 12:51 AM
20" is a good comprimise between velocity and weight & handling. This is my DPMS 20" Varmint / Target rig with 1-9" 223 bbl RRA 2 Stage trigger and 6-18x44mm target dot scope. These targets were shot with 50gr American Eagle non match grade ammo. These are the only 100yrd groups with this rifle that I have scanned in (my first outing with it). I've shot Black Hills, Federal GMM, and an assortment of Handloads with even better results.

http://i124.photobucket.com/albums/p38/jpwilly/ARBULL20-1.jpg

http://i124.photobucket.com/albums/p38/jpwilly/5shots100yrdsFAE.jpg

http://i124.photobucket.com/albums/p38/jpwilly/3shotsat100yrdshalfFAE.jpg

http://i124.photobucket.com/albums/p38/jpwilly/3shotsat100yrdsFAE.jpg

lej
February 21, 2009, 02:33 AM
Quote:
The .223's wound mechanism is largely fragmentation

Maybe if you are using FMJ, but not hunting rounds. I use hunting rounds for deer and defense loads. I do not rely on fragmentation. A 60 gr Nosler or a 64 gr Power Point on bigger game and V-Max type bullets on the smaller stuff.
----------------------------------

right you are knight interceptor for some reason i had jacketed and match grade rounds on the brain. the nosler partition is a great hunting round think its expansion threshold is down to about 1800fps or there abouts

sang716
February 21, 2009, 07:26 AM
i like my bushy with a 14.5''. seems to shoot better than i can.

RedNoma
February 22, 2009, 01:24 AM
Go with the 20". I have a 24" and plan on having it cut, recrowned and fluted. It's pretty much a bench/bag queen right now.

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