Is a 20 inch barrel good enough for a 308 hunting rifle?


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Cal-gun Fan
March 9, 2012, 02:01 AM
Basically as the title says. I'd prefer the shorter barrel if that would not affect velocity too negatively.

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wlewisiii
March 9, 2012, 02:05 AM
Depends on who you believe.

I have a 19" barrel on my primary hunting rifle in 7x57. I haven't noticed any issues with it. YMWV.

Onmilo
March 9, 2012, 02:10 AM
yes.

AK_Maine_iac
March 9, 2012, 02:19 AM
I have a 308 with 18 inch bbl, Old Remington 660 , My AR10 w/20 inch bbl, and a Howa 308 w/24 inch bbl. I would not hesitate to take anyone of them hunting.
The only problem with the 660 in 308. You do need a burn permit from the BLM or state forestry service. She is a flame thrower.

RPRNY
March 9, 2012, 02:19 AM
Velocity should not be negatively affected by a 20" barrel length unless you are loading with a very slow burning or progressive powder. Generally speaking, with most conventional smokeless powders achieve full burn and, therefore, essentially peak velocity by the 16" - 18" range.

The other question that may be relevant is the barrel twist rate and intended bullet weight. 1 in 12 is pretty common for .308 so unless you are cutting down a barrel with a lesser rate of twist and/or intent on using very heavy for caliber bullets, anything in the 150 - 180 gr range should adequately stabilize in a 20" barrel. 20" is a good length.

firesky101
March 9, 2012, 02:29 AM
If the extra fps makes the difference you should be looking at another caliber. That said I feel 20" to be perfectly adequate for .308.

Dmitri Popov
March 9, 2012, 03:15 AM
Yep, It'll kill just as dead as anthing else.

Ar180shooter
March 9, 2012, 03:19 AM
You'll lose maybe 50 fps going with a 20" compared to a 24"... not something I would be concerned about.

TexasPatriot.308
March 9, 2012, 03:36 AM
I have AR10s with 20" barrels, shooot a long, long way with em.

lefteyedom
March 9, 2012, 03:52 AM
I have had several rifle barrels shorten to 20", 30/06, 308, 7-08, and even a 45/70.

What ever lost muzzle velocity was more than made up for in handling.

A well balanced firearm is a fine hunting rifle.

jmr40
March 9, 2012, 08:15 AM
Yes!

Art Eatman
March 9, 2012, 09:00 AM
My understanding is that the .308 was among the first where a computer was used in the design. The idea was to replicate factory '06 performance with a 150-grain bullet at some 2,800 ft/sec, when using barrels in the range of 18" to 22".

Seems like they accomplished their goal...

Skyshot
March 9, 2012, 09:05 AM
308's perform wonderfully out of short barrels, You do loose a little velocity the shorter you get but IMO it doesn't affect the .308 as bad as it does other cartridges based on the same case like the .243 and .260 ect. An 18 inch .308 makes for a nice light weight unit and is still capable of reaching out at a good distance.

Cocked & Locked
March 9, 2012, 09:05 AM
20" barrel is fine. My Remington Model Seven .308 is a 20 incher and is great...short, light, and good to go.

http://pic90.picturetrail.com/VOL2169/3082611/17383006/400977564.jpg

bpl
March 9, 2012, 11:11 AM
Yes:-)

Z-Michigan
March 9, 2012, 11:12 AM
In .308, the only reason to go longer than 20" is for F-Class competition.

Cal-gun Fan
March 9, 2012, 11:27 AM
Ok, thanks a lot guys!

jmr40
March 9, 2012, 01:26 PM
therefore, essentially peak velocity by the 16" - 18" range.



Not true. A 308 or any other cartridge will continue to to increase in velocity well beyond 18". It becomes a question of how much. A 26" barrrel will give you about 250 fps more velocity than a 16" barrel. The difference between 22"-24" barrel and a shorter 20" barrel is not that great. Around 50-75 fps, 100 at most.

But the 308 is more efficient than most and the difference would be much greater with many other rounds. I'm of the opinion that 20" is a good length for the 308. You still get good velocity at that length and would have to go to 28-30" to see a notable improvement. But that is also about as short as I'd want. You do start to see notable decreases in velocity when you drop under 20". But probably the biggest problem is that muzzle blast becomes a major concern.

jpwilly
March 9, 2012, 01:45 PM
20" is plenty good.

Z-Michigan
March 9, 2012, 02:00 PM
More on .308 barrel length and velocity...

http://www.tacticaloperations.com/SWATbarrel/

mac66
March 9, 2012, 02:42 PM
My go to hunting rifle for the last 25 years is a Winchester Mod 70 308 w/20" bbl, 2-7 Leopold scope. It has taken whitetail, mule deer, antelope, caribou, black bear out to 400 yards. I have not found anything better than that rifle.

biggameballs
March 9, 2012, 02:44 PM
Yes a 308 was designed to be effecient enough to get close to max performance out of a shorter barrel.

Carne Frio
March 9, 2012, 10:35 PM
Here is a link to some data, comparing 3 different loads using
16, 20 and 24 inch .308 barrel lengths. Average 20 fps per inch
difference, or less.

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2177339

Dr T
March 9, 2012, 11:29 PM
My Ruger Frontier 308 has a 16.5" barrel. I can't say that the deer have noticed...It is awfully handy in the pickup.

Maxicooper
March 9, 2012, 11:54 PM
CZ 550 FS .308win, 20.5" barrel ;)

http://farm8.staticflickr.com/7197/6898725781_b4c114c1af_z.jpg

denton
March 10, 2012, 12:19 AM
One of my favorite long guns is a 600 in 308, with an 18" barrel.

It does not give me as much MV as a 22 or 24, but it is light, handy, and plenty potent. And when you touch it off, there isn't any question about whether it lit or not!

How much you lose by cutting off an inch of barrel depends on the bullet, the powder, and how long the barrel was before you cut the inch off. Cutting an inch off a 29" barrel probably costs you roughly 15 FPS. Cutting an inch off an 18" barrel probably costs you more like 35-50 FPS. The powder burns out long before the bullet reaches the muzzle, but the compressed gas continues to accelerate the bullet.

The muzzle flash you see is because the compressed gas is out of oxygen but hot enough to glow. When it hits the air, some components in the gas re-ignite. It would be really unusual for still burning powder to reach the muzzle.

With a short barrel, bullet selection becomes more important. Sierra hunting bullets tend to need to impact at about 2100 FPS to open reliably. Nosler Partitions open reliably at 1800 FPS. So with a Partition, your bullet will open at longer range. There are plenty of bullets that will do this.

IIRC, with 165 grain bullets a max load gives me around 2650 FPS but I load down to 2550 FPS for comfort. It's quite adequate for anything within 350 yards. If I need to reach beyond that, there had better be a darn good reason.

heeler
March 10, 2012, 12:33 AM
I have used my old 1972 built Remington 600 Mohawk in 308,equipped with the factory 18.5 inch barrel for several years walk hunting for deer and hogs with very lethal results.
I had a guy with an Ohler cronograph measure a three shot group of mine using Federal Premium 165 gr.BTSP coming out of that 18.5 barrel and the average was 2550 fps three feet in front of the muzzle.
I dropped a buck at a lazered 244 yards DRT with that rifle and ammo combination.
A .308 can handle a short barrel quite well and still retain efficient killing power down the distance line.

browningguy
March 10, 2012, 01:26 AM
They work fine, I have a Ruger 77 RSi with the 18.5" barrel in .308, and two 30-06's with 20.5" and 18" barrels.

http://img.photobucket.com/albums/v11/jcm9371/Rifles/rugerrsi.jpg

http://img.photobucket.com/albums/v11/jcm9371/Rifles/Sako3006-1.jpg

http://img.photobucket.com/albums/v11/jcm9371/Rifles/slb2000-2.jpg

helotaxi
March 10, 2012, 09:59 AM
Velocity should not be negatively affected by a 20" barrel length unless you are loading with a very slow burning or progressive powder. Generally speaking, with most conventional smokeless powders achieve full burn and, therefore, essentially peak velocity by the 16" - 18" range.
It doesn't work that way. Percent of burn is not usually even worth looking at. Most .308 loads don't completely burn the powder charge in a 26" barrel. 3031 is the notable exception to that. The .308 in particular has a very large expansion ratio for its case capacity. This means that it doesn't maintain pressure very well and also means that slower powders can't build pressure fast enough to reach peak allowable pressure before the volume behind the bullet has increased at a rate faster than the gases from the burning propellant expands. For this reason, .308s like medium-fast rifle powders. Also for this reason the .308 doesn't generate enough gases to see a lot of benefit from a long barrel. Compare this to a cartridge with a high case volume to bore ratio and a low expansion ratio. Cartridges such as the .243, .25-06 and 7mm Mag benefit greatly from a longer barrel because the smaller bore in relation to the powder charge means that a lot of gas volume is created and pressure is maintained at a higher level for a longer length of bore.

The other question that may be relevant is the barrel twist rate and intended bullet weight. 1 in 12 is pretty common for .308 so unless you are cutting down a barrel with a lesser rate of twist and/or intent on using very heavy for caliber bullets, anything in the 150 - 180 gr range should adequately stabilize in a 20" barrel. 20" is a good length.The difference in velocity for the various barrel lengths in the .308 means that the barrel twist is either fast enough or not independent of the barrel length. Within the normal velocity range of the .308 the difference in the Miller Stability Index for a particular bullet isn't affected appreciably by the 250fps or so difference in velocity between a 16" and 26" barrel.

Averageman
March 10, 2012, 10:02 AM
18 inch barrels would seem to me to be about perfect for a .308.

helotaxi
March 10, 2012, 10:13 AM
Other than muzzle blast, I would not disagree if it was intended for hunting purposes. If legal, 16" with a suppressor would be about perfect IMO.

uvausmc
March 10, 2012, 11:10 AM
My Ruger Frontier killed two whitetails back to back a few seasons ago. They never noticed that I only had a 16" barrel. As long as you're not looking at shooting extreme ranges <20" is fine. Also remember the shorter the barrel the stiffer it is so it is theoretically more accurate.

http://i253.photobucket.com/albums/hh41/uvausmc/RugerFrontier1.jpg

Redneck with a 40
March 10, 2012, 11:20 AM
I've got a Remington 700 SPS tactical in .308 with a 20" barrel. I only punch paper with this thing out to 350 yards and its sweet! Short, handy, powerfull and fun!

243winxb
March 10, 2012, 11:36 AM
20" = less velocity + More noise.

jerkface11
March 10, 2012, 12:00 PM
If it were a .30-30 would you be asking if a 20" barrel was long enough?

T.R.
March 10, 2012, 12:02 PM
This dandy antelope buck was taken at well over 300 long strides. My 20 inch barrel .308 performed flawlessly at this long range. Plain FEDERAL Classic ammo was used.

TR

http://i26.photobucket.com/albums/c146/rushmoreman/JFlongshotfin.jpg

helotaxi
March 10, 2012, 12:05 PM
"Less" is only relevant in context. The argument could be made that 26" offers less velocity than 30" and more noise so the 30" is better. The argument could also be made that 20" offers more velocity and less noise than a 16".

"Less" and "more" are not the argument that relevant. "Adequate" and "acceptable" are the salient points. Velocity is certainly adequate from a 20" barrel for the .308 and whether the noise level is acceptable is up to the individual.

ball3006
March 10, 2012, 12:17 PM
Several deer that I shot with my 18 inch barreled carbine didn't notice the barrel was too short by some people's standards...........chris3

denton
March 10, 2012, 09:45 PM
Most .308 loads don't completely burn the powder charge in a 26" barrel.

Common misconception, I'm afraid.

People see muzzle flash, and assume that the powder is still burning. In almost every case, the powder is all burned in less than a foot. The muzzle flash is bright for two reasons: 1) The propellant gas is hot enough to glow, even though the fire is out, and 2) The propellant gas contains hydrogen and other flammable products. When these hit open air, they have oxygen again, and re-ignite.

helotaxi
March 11, 2012, 05:36 AM
Based on Quickload simulations, not muzzle flash. Muzzle flash indicates pressure, nothing else. Regardless, completeness of burn isn't a valid goal for either velocity or accuracy. Almost no rifle completely burns the powder charge in a barrel of reasonable length. If it did, then there would be significant wasted pressure potential and lost velocity.

Fremmer
March 11, 2012, 10:55 AM
hbeautiful rifle maxi. like that full stock.

FMF Doc
March 11, 2012, 11:01 AM
I would say no, as long as it is stiff enough, and has good harmonics. The USMC Sniper rifle the M40A5 has a 20" barrel, and they seem to do just fine with it. No complaints out to 1000m.

Art Eatman
March 11, 2012, 11:46 AM
Looks like the question is quite well-answered. :)

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