20" or 26" That is the question

[OregonPlinker]

Im thinking my next rifle should be a 308 bolt gun. I already have it narrowed down to the Remington 700 SPS. I just cant decide if I want the tactical 20" barrel or the 26". I have a 223 with the 26" barrel. If I got the 26" it would match the 223 and give me a few more feet per second. If I got the 20" it would be a little more balanced and not as much of a bench/prone gun. What Im wondering is how much the 6" difference is going to make past 500 yards. It will mostly be a paper/steel puncher but I might take it hunting if I get the urge... I usually take the 270 for deer and 7mag for elk so I dont NEED it for hunting. Mostly just to have and enjoy. Pros, cons, opinions... Lets hear them. Thanks guys

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[JC9995]

The Rifle Barrel

By Chuck Hawks



Velocity loss (or gain)

It is worth noting that the velocity figures published in ammunition brochures and reloading manuals are sometimes taken in barrels different in length from those supplied on many rifles. I have seen various estimates of how much velocity is lost (or gained) when a barrel is not the same length as the test barrel in which a cartridge was chronographed. Here are some of them.

The 2001 Edition of the Shooter's Bible states, in the introduction to the Centerfire Rifle Ballistics section, "Barrel length affects velocity, and at various rates depending on the load. As a rule, figure 50 fps per inch of barrel, plus or minus, if your barrel is longer or shorter than 22 inches." However, they do not say what category of load to which this 50 fps average pertains.

Jack O'Connor wrote in The Rifle Book that, "The barrel shorter than standard has a velocity loss which averages about 25 foot-seconds for every inch cut off the barrel. Likewise, there is a velocity gain with a longer barrel." He went on to illustrate this using a .30-06 rifle shooting 180 grain bullets as an example, so his estimate was obviously for rifles in that general performance class.

Other authorities have tried to take into account the different velocity ranges within which modern cartridges operate. The Remington Catalog 2003 includes a "Centerfire Rifle Velocity Vs. Barrel Length" table that shows the following velocity changes for barrels shorter or longer than the test barrel length:

MV 2000-2500 fps, the approximate change in MV per 1" change in barrel length is 10 fps.
MV 2500-3000 fps, the approximate change in MV per 1" change in barrel length is 20 fps.
MV 3000-3500 fps, the approximate change in MV per 1" change in barrel length is 30 fps.
MV 3500-4000 fps, the approximate change in MV per 1" change in barrel length is 40 fps.
The 45th Edition of the Lyman Reloading Handbook also has a table showing Center Fire Rifle Velocity Vs. Barrel Length. Their figures apply to barrels between 20 and 26 inches in length and agree with the Remington figures. The Lyman table shows the following approximate velocity changes:

For rifles with muzzle velocities in the 1000-2000 fps range, the change in velocity for each 1" change in barrel length is 5 fps.
For rifles with muzzle velocities in the 2001-2500 fps range, the change in velocity for each 1" change in barrel length is 10 fps.
For rifles with muzzle velocities in the 2501-3000 fps range, the change in velocity for each 1" change in barrel length is 20 fps.
For rifles with muzzle velocities in the 3001-3500 fps range, the change in velocity for each 1" change in barrel length is 30 fps.
For rifles with muzzle velocities in the 3501-4000 fps range, the change in velocity for each 1" change in barrel length is 40 fps.

The 43rd edition of the Lyman reloading Handbook gave some concrete examples of velocity loss for specific calibers and loads. The Lyman technicians chronographed some high velocity cartridges in rifles with barrels ranging in length from 26 inches down to 22 inches with the following results:

The average loss for the .243 Win./100 grain bullet was 29 fps per inch.
The average loss for the .264 Win. Mag./140 grain bullet was 32 fps per inch.
The average loss for the .300 H&H Mag./220 grain bullet was 25 fps per inch.

For standard high intensity cartridges in the same test, the Lyman technicians chronographed the cartridges in barrel lengths ranging in length from 24 inches down to 20 inches with the following results:

The average loss for the .270 Win./130 grain bullet was 37 fps per inch.
The average loss for the .270 Win./150 grain bullet was 32 fps per inch.
The average loss for the .300 Sav./180 grain bullet was 17 fps per inch.
The average loss for the .30-06/180 grain bullet was 15 fps per inch.
The average loss for the .35 Rem./200 grain bullet was 11 fps per inch.

After a bunch of disclaimers, the Lyman people concluded, "The rule of thumb is that high speed, high pressure cartridges shed more speed in short barrels than do the low speed, large bore types." It's funny, but that is what I had suspected all along!

 

[JC9995]

So...now that you've read all that.....

I was at a local range a few weeks ago. I was shooting next to a gent that had a new 700sps in 308, the new 20" tactical version. That thing threw a huge fireball out the end. He was using factory loads.... So that tells me he was wasting a bunch of potential velocity. I have the same rifle and caliber but in the varmint version.... And it doesn't exhibit the same fire breathing temperament.

Cheers.

 

[BillyDa59]

Just personal opinion, but I've always thought the notion of a "tactical" shorter barrel was plain silly. If I was getting a new bolt gun, I'd want the barrel to be as long as possible. Longer barrels give a slight edge in ballistics and are probably marginally quieter -- I'd say that's more "tactically" appropriate for a bolt action than a short barrel. Are you going to clear a house with your rifle? But then you ask for quantification of the 6" difference. I'll have to defer answering of specifics to someone else. I honestly don't know how much barrel length effects ballistics and sound, I just know that it does.

I suppose you also stated you have all the hunting rifles you need, so this gun is strictly for vanity's sake. In that case, if you want the "tactical" short barrel, go for it. Whatever you think looks nicer. I just tend to think of things in terms of practicality, and I think 26" is more practical for a bolt action rifle.

EDIT: I hadn't seen the second post in this thread prior to my posting this.

 

[orygun]

If you want a bench gun, get the 26". If you want a gun to use for anything else, get the 20".
I'd prefer a 22" barrel for any 308 I would own (I own none) but with these 2 choices, I'd go with the 20".

 

[geometro]

20" is perfectly fine past 500 yds. You'll just have to dial in a touch more elevation...

If you go with the AAC-SD version you'll get the 1-10" twist which are theoretically better for heavier bullets and have an option to go with a suppressor in the future if you chose to do so.

 

[jonn5335]

I think you should get what fits your needs. That being said I would get a 30" tube and pack the powder in the case with a pencil eraser and top it off with a 210 SMK but then again that's just me :gun20:

 

[Mark W.]

26" is a rifle.
20" is a carbine.

Rifle is for long range.
Carbine is for riding on a horse.

Been that way since the Civil War. Nothing we come up with now is going to change that.

 

[FarmerTed1971]

Go 26", I did.

 

[BillyDa59]

That's an awfully purdy rifle you got there. Is that just a Rem 700 in another company's custom stock? How's it shoot?

 

[Jamie6.5]

20" is more rigid, and less susceptible to barrel "whip," and vibration.
26" allows for more velocity with slower powders, but needs a much larger O.D. to be as rigid.

If accuracy (in a .308Win) is what you're after, I'd go with a 20", especially if a large O.D varmint or target barrel is offered, but that's just me.
It's not like a .308 Win needs a long barrel due to case capacity like a .300WM or .300UM does.

Then think about how large a 26" barrel has to be to match a 20" heavy-barrel's lack of flex and vibration-at-the-muzzle.
Like on the Remmy LTR (Light Tactical Rifle) for instance.

YMMV.

 

[sealine]

So...now that you've read all that.....

I was at a local range a few weeks ago. I was shooting next to a gent that had a new 700sps in 308, the new 20" tactical version. That thing threw a huge fireball out the end. He was using factory loads.... So that tells me he was wasting a bunch of potential velocity. I have the same rifle and caliber but in the varmint version.... And it doesn't exhibit the same fire breathing temperament.

Cheers.

If you were at Tri-County gun club, the guy with the .308 SPS Tactical, throwing the huge fireball could have been me. When I shoot factory PMC through it, it will throw a huge flash out of the muzzle. And the sound decible is noticeably louder. I'm not exactly sure why this is; could be because of the type of powder that PMC uses. When I shoot handloads with 42 grains of Varget or any factory ammo other than PMC, there is no noticeable muzzle flash.

 

[Mark W.]

OK lets look at this another way.

The SAVAGE company team is one of the best long range teams in the country in F class and F T/R they use factory rifles

The Savage model 12 Plama has a 30" barrel it's only offered in .308
The Savage model 12 Long Range Precision has a 26" barrel offered in .243 win .260 rem and 6.5 creedmore
The Savage model 12 F T/R has a 30" barrel offered in .223 and .308
The Savage model 12 F class has a 30" barrel offered in 6 NormaBR and 6.5 X 284 Norma
The Savage model 12 Benchrest has a 29" barrel offered in .308win, 6 NormaBR and 6.5 X 284 Norma

Obviously if Savage Factory rifles are some of the top performing long range rifles in Team competition and they are using 26" to 30" barrels there must not be an advantage to a 20" barrel for long range shooting and if there is no advantage it might also mean there is a disadvantage.

LONG BARRELS MAKE BULLETS FLY STRAIGHTER.

 

[Luke2236]

I have the 26" r700 sps. Last time I took it auto was hitting eggs off the top of pop cans at over 350 yards. I was able to do this with almost every shot and I never hit a can. This gun is accurate! This is way better than my old 20" I owned years ago.


Sent from my Nexus 7 using Tapatalk 2

 

[KalamaMark]

I'll never have a barrel longer than 22" on a hunting rifle again.

I've got a Model 70 Classic with a 24" barrel and then the BOSS compensator hanging off the end, and it's like carrying a flagpole on your shoulder.

The barrel catches on every twig, vine, stick, branch for a mile around. Here on the wet side, there are a lot of twigs, vines, sticks and branches in a 1-mile circle!!!

 

[Mark W.]

I'll never have a barrel longer than 22" on a hunting rifle again.

I've got a Model 70 Classic with a 24" barrel and then the BOSS compensator hanging off the end, and it's like carrying a flagpole on your shoulder.

The barrel catches on every twig, vine, stick, branch for a mile around. Here on the wet side, there are a lot of twigs, vines, sticks and branches in a 1-mile circle!!!

All true OP was asking about a primaraly 500 yard+ rifle to punch paper or bang steel. That might go hunting not a brush gun

 

[OregonPlinker]

I'll never have a barrel longer than 22" on a hunting rifle again.

I've got a Model 70 Classic with a 24" barrel and then the BOSS compensator hanging off the end, and it's like carrying a flagpole on your shoulder.

The barrel catches on every twig, vine, stick, branch for a mile around. Here on the wet side, there are a lot of twigs, vines, sticks and branches in a 1-mile circle!!!

I agree for a hunting rifle. I have a 25-06 and a 7mag with 24 inch barrels and that 223 with the 26 inch bull. It is annoying in the woods, and the bull barrel weighs a ton compared to regular barrels. My buddy actually carry's a youth model 243 during hunting season for this exact reason. It seems like its a toy when you handle it but its a great brush gun. He gets deer and elk every year with it. He even got a cougar a couple years ago with it...

 

[orygun]

LONG BARRELS MAKE BULLETS FLY STRAIGHTER.

You're not the same guy that said that he'd seen a .270 bullet bounce right off of an elk's hindquarters, are you?

 

[Mark W.]

You're not the same guy that said that he'd seen a .270 bullet bounce right off of an elk's hindquarters, are you?

nope

 

[mrblond]

You're not the same guy that said that he'd seen a .270 bullet bounce right off of an elk's hindquarters, are you?

Did that Elk have a big S on its chest?