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Old November 10, 2023, 02:48 PM   #1
RAfiringline
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.308 - best barrel length?

The title pretty much says it.

1] 16 inch seems short to me - maybe too much power and accuracy loss out to 500 meters.
2] 18, 20, 22 inch seems like they might be ok.
3] 24 inch is too long, un-wieldly.

There are plenty of people in here who know more about this than I do; the use of the rifle would be fun shooting and survival in the unlikely(?) case things go way bad.

Thanks, RA
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Old November 10, 2023, 04:25 PM   #2
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I believe 20" is optimal.
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Old November 10, 2023, 04:56 PM   #3
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First question is always, what do you want it to do best??

Get the most possible out of the round within practical limits??
Or get the best handling rifle accepting the sacrifice in performance to gain "portability"??

I began deer hunting with an 18.5" barrel .308 carbine. Still have the rifle. I also have a 22" barrel (standard) rack grade M1A.

The difference in muzzle blast and flash is astounding!

16" is the Federal legal rifle minimum, but some states require 18" for legal hunting.

If you're moving in thick vegetation, or in and out of vehicles or inside buildings, the shorter barrels are definitely better. If not, longer tubes give more of the of what the round has to offer. It's entirely up to you to decide which is best for you.
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Old November 11, 2023, 10:21 PM   #4
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Not a .308, but for my .338 Federal, I went 16”.

Built it to be a short(er) range, woods/brush gun.

Also built it with the intent of running it suppressed most of the time, which adds about 9” if I recall correctly.

Both those factors sent me to a 16” to keep the length down (and shaves a tiny bit of weight), especially with the suppressor on. Not really worried about any velocity lost, the ranges I intend to use the rifle, it won’t be noticeable.

Accuracy wise, I get 1.5-2” at 100 yards, which is good enough for, me for a hunting rifle.
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Old November 12, 2023, 12:55 PM   #5
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As a general use rifle I like 20" for a 308 and can live with 22". You just don't gain much going longer than 20" unless you go all the way to 28".

A 16" or 18" barrel isn't a bad choice for special purpose uses. I wouldn't mind one that short for some situations.
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Old November 28, 2023, 04:24 PM   #6
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I think 20" is the perfect compromise between speed, unburnt powder, noise, etc. Note that I am biased though. I think people with 10" AR15's are insane.
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Old November 28, 2023, 10:59 PM   #7
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I switched to using an 18 inch pencil barrel last year for hunting. It’s killed one deer and one hog just fine so far. Admittedly I would have preferred a 20 inch but it’s hard to find pencil barrels for AR10 platform rifles.
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Old November 29, 2023, 10:45 AM   #8
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Totally depends upon intended use.

From my experience, a shorter barrel may not be the most accurate and tends to give up muzzle velocity and kinetic energy if you shoot long distances.

For a hunter stalking in heavy brush, a 20-inch barrels may be too long.
For a bench shooter trying for repeatable accuracy, 24-inches may be too short.

I am very happy with my 24-inch .308s that I shoot from a bench, but the barrel in my next .308 probably will be 26-inches, like my more accurate .223 and 6.5mm bolt Savages.
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Old November 29, 2023, 02:20 PM   #9
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First off you don't loose any accuracy from a short barrel. Either the barrel is an accurate one or it isn't. You do have to correct more for drop and drift due to velocity loss, but again that isn't an accuracy issue.

16" in a .308 will do most things well, but it does fall apart at a certain distance. Rifle Shooter Magazine did a write up a few years ago on cutting down a .308 Win. Just realize their rifle isn't your rifle and you could have far different results.

Do you want to own a suppressor, then I'd go with a 16-18" barrel. If you don't care about shooting suppressed, then a 20-22" will be your huckleberry. If you want to shoot long range 26"+ is where I'd start.

Survival, what kind of survival? If you're talking gathering food, snares and a rimfire rifle will do the majority of that. If you're talking something more dystopian, then you're better off avoiding situations where a .308 is needed.
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Old November 29, 2023, 05:44 PM   #10
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I have a 22" 788, a 20" VTR, and an 18" BAR MK3. Wasn't any difference between the 788 and VTR. I'm estimating 100fps from the 18 and will chrono after hunting season. I use 308 on the lease where I don't have more than 250 yard shots, anyhoo.
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Old November 29, 2023, 06:04 PM   #11
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Bolt gun or gas gun?

Suppressor use or no?

Hunting, bench, some type of competition?

What loads?

I have an 18, 20 and 24 inch in .308. The first is on a gas gun for 3Gun Heavy shooting 140s at about 2800, the 20" is a kick around, back-up for hunting and I shoot 165s at about 2700. The 24 is more of a trainer that is mostly shot at the range from the bench and prone. It is integrally suppressed and sees a lot of different bullets, from 165s to 240 grain subs. For those purposes, those are the best lengths for me.
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Old November 29, 2023, 07:31 PM   #12
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20" for a short action bolt rifle, BLR or Long Ranger.

18" would suit me for an AR10.
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Old November 30, 2023, 12:06 AM   #13
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16.25 inches is the FNH Scar 17S standard barrel . For that particular carbine it does a fine job . I still shake my head at the 1in 12 twist rate.
The Sierra Gold Medal Match 168gr. shoot great out of it. REM. 150 gr. Core loct group at 1.25 “ at 100 yds. My own Hornady ELD match 168 gr. Are okay but Varget is not the optimum powder choice .( still looking).
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Old November 30, 2023, 09:50 AM   #14
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I don't find a 26 inch barrel unwieldy.
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Old November 30, 2023, 11:01 AM   #15
MarkCO
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Quote:
Originally Posted by Hawg View Post
I don't find a 26 inch barrel unwieldy.
Was not the question. It is, what is best. Anything past 22 inches for the .308 won't even be in the conversation for best based on the data. Only a few magnums can even take advantage of 26 inches.
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Old November 30, 2023, 12:59 PM   #16
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Quote:
Anything past 22 inches for the .308 won't even be in the conversation for best based on the data.
If you define "best" by highest velocity, then I'd agree.

Other folks use other criteria, and some use a combination of criteria to determine what they consider "best".

Since we're in the semi auto forum, the usual barrel lengths for semi auto rifles ought to be the primary topic. That would basically be 16, 18, 20, and 22" tubes as far as I can see.

Semi auto .308 sporting rifles, like the Rem series are usually in either 22" or carbine 18" (18.5") length. Military style semis like the M1A, FAL, H&K 91, and ARs are available in other lengths as well.

OP did not state the rifle he was considering, only the use he would put it to.

I've had a bit of experience with all the common semis having 18" or longer, but not the 16" ones.

At my stage of life, climbing rifle armed in and out of vehicles, house clearing and CQB situations are simply not options. Hunting in thick cover still is, but while I have hunted with battle rifles, I choose not to pack more weight and length than needed into thick woods. My first deer rifle was a Remington 600 bolt action .308 with an 18.5" barrel. That's still my preferred size and weight class for the deer woods. I'd choose that over any semi auto.

If I were "hunting" something that would hunt me back, (or vise versa) my choice would be different. I am very fond of my "rack grade" M1A. Fits me well, has a good trigger, and there is a strong nostalgia bond for me. Also its as or more accurate than I am in field conditions and dead nuts reliable. Have had all the others, and eventually let them go. The M1A is the one I kept, and will keep. Can't buy or sell one in my state these days (until they get that stupid law repealed) but I can, and will keep mine, until they close the lid on my box.
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Old November 30, 2023, 02:25 PM   #17
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Quote:
Originally Posted by 44 AMP View Post
If you define "best" by highest velocity, then I'd agree.

Other folks use other criteria, and some use a combination of criteria to determine what they consider "best".

OP did not state the rifle he was considering, only the use he would put it to.

I've had a bit of experience with all the common semis having 18" or longer, but not the 16" ones.
I've owned 308 Pattern ARs with 16, 18, 20, 21, 22 and 24 inches. I've shot shorter ones. The 24" had the highest velocity, but was not the most accurate, and it was heavy as a manhole cover. The 16" and shorter were loud with concussion that was uncomfortable unless suppressed.

Best is, "for purpose" and a general multi-use is usually what I define to be the best for an AR pattern. I've shot Deer, Pronghorn, Elk and lots of smaller game, including predators and hogs with .308 pattern ARs. I don't prefer them, so unless hogs are on the menu, I usually default to a bolt gun.

I "think" I am done fiddling and experimenting with the .308 pattern ARs. The Stag based 18" .308 is what I use for Heavy in 3Gun and the 22" 6.5CM is what I use for gas gun precision matches and hogs.
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Old December 1, 2023, 10:57 AM   #18
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I like the 20" length best in a full size rifle .

But in a carbine or short , lightweight rifle ...18" will do nicely . I have a short light 1895 Mauser Sporter in 7 X 57 with a 18" bbl and it carries and shoots well , especially in the under brush .

I also have a Custom Springfield Sporter 30-06 Rifle built on a 1903-A3 Springfield bolt action , with a 22" barrel and it is not a problem to carry and shoot with ...

18" to 22" are all good but to pick one length ... go with the 20" !
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Old December 1, 2023, 12:30 PM   #19
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Originally Posted by gwpercle View Post
18" to 22" are all good but to pick one length ... go with the 20" !
Gary
I think we are "talking amongst ourselves" as the OP has not been back to the thread in 3 weeks. Probably talking .308 pattern auto-loaders, but still not sure.

I'd be good with 20" for one length to do all.
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Old December 3, 2023, 02:14 PM   #20
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Quote:
.308 - best barrel length?
The title pretty much says it.
1] 16 inch seems short to me - maybe too much power and accuracy loss out to 500 meters.
2] 18, 20, 22 inch seems like they might be ok.
3] 24 inch is too long, un-wieldy
What platform? Semi-auto (which is this sub-forum)?

With a 16" barrel, my 7.62/.308 LMT LM8 is a perfect length since I run a can on it.

Figure a 6"-7" .30-cal can adds another 3"-4" past the MB or FH device that it attaches to (it comes back a bit over the muzzle device, not a direct thread). Thus, cumulative OAL is 19"-20" (16" + 3" or 4").

I also have an 18" LMT SPR barrel for it but with the can on it starts to get unwieldy when shooting other than prone.
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Old December 7, 2023, 06:37 PM   #21
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The change in Maximum Point Blank Range for M80 Ball going from a 28 inch barrel to a 16.5 inch barrel is you lose 29 yards.

The average over the ammunition tested was a 27 yard loss. That is going from 325 yards MPBR to a 296 MPBR.

Quote:
Note the change in MPBR averages 27 yards with an 11.5 inch change in barrel length.
https://rifleshooter.com/2014/12/308...ty-28-to-16-5/
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Old December 14, 2023, 10:34 PM   #22
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It depends on the caliber and what you are doing with it.
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