I have two of the Savage .308 Tactical rifles, one with a 20" barrel, and one with a 24" barrel.

My question is this: how much difference is there between the two barrel lengths?  And I'm not just talking about ballistics, but also about the suitability of the guns to various roles.  I'm trying to figure out how to equip them, and thier capabilities will determine how that goes.

24 if it's gonna be a bench gun

If your going to be carrying it around in the woods a 20" is fine.

24" = bench

20" = everything else

If you're trying to shoot to 1000 yards, the 20" is not going to offer you any help. If you're strolling through thick brush, the 24 is going to get hung up more. What are your intentions with these rifles? Without answering that, we're pissin' in the wind.

Both guns are heavy-barreled rifles so I'm not going to be using them as brush guns.  I have some other stuff to fill that need.  

What I'm trying to do is turn them into solid tactical rifles.  While I sincerely hope I should never need them for that purpose, I'd like them to be capable of serving in that capacity if needed.  In all likelihood they will serve mostly as bench rifles, and occasionally as varmint or hunting rifles.

I'd keep the 20," sell the 24," and use the money to fund the purchase of a quality scope.  As you probably know, shorter barrels are generally more accurate (all other dimensions being equal) and the only advantage a longer barrel provides is greater velocity (to a point) and possibly decreased muzzle signature.  The general opinion seems to be that the performance characteristics between a 20" and a 24" .308 barrel are negligible.  

You might be interested in Jeff Cooper's Scout Rifle concept if you aren't already familiar.      

Link to the AR15.com Precision Rifle forum

barrel length effects velocity to a point.

a bullet going trans sonic decreases accuracy

Under 700 yards there is no difference between the two rifles

at 1000 yards both rifles accuracy WILL be effected by going trans sonic in both rifles.

I'd go with 21-3/4" for the best accuracy out to about 1200y, then  longer is better.....

1200 yards is a long ways for a .308.  Generally speaking the maximum effective engagement range for the .308 end is around 800m, although the USMC pushes it to 900m.

With a Sierra 175 gr MK (as in the M118LR) it does a little better past 800m in terms of maintaining supersonic velocity out to about 950m, but it's still dropping like a rock and losing the consistency that makes the .308 worth shooting.  With a 168 gr Sierra (M852) or 173 gr FMJ (M118), it runs out of steam around 800-850m.

In all of the above cases, that's with a 24" barrel.  While I agree to a point that a 22" (or so)  barrel is probably a good compromise for shortish range shooting, the suggestion that a 21 3/4" barrel is GTG for anything up to 1200 yards and that 24" should be used for anything over that is a little stupid as 1200 yards is already outside the reasonable envelope for the .308.  But it does help illustrate the problem with going shorter than 24".

When you shorten a .308 from 24" to 20" two things happen:

1) you lose about 80 fps (there is about 20 fps per inch of barrel loss between 20" and 24"); and worse

2) the standard deviation in velocity usually increases.  

In the best case, with the 175 gr MK, an 80 fps velocity loss at the muzzle when considered downrange at 800m is only going to cost you about 2 MOA in additional elevation correction and 1 MOA in windage correction (10 kt full value crosswind) compared to the 24" velocity.  But losing 4" of barrel will also tend to increase the standard deviation in velocity.  This means a load that may have had an SD of 10 and an extreme spread in velocity of about 30 fps, now has an SD of maybe 25 fps and an ES of 75 fps, so now you potentially need another minute or two of elevation correction over and above the 2 MOA you lost with the 80 fps velocity reduction due to the shorter barrel, but it's now inconsistent from shot to shot and you have now way of knowing.  Long range accuracy is all about consistency and that is the only advantage the .308 has going for it compared to larger cartridges, but you screw it up by going with a shorter barrel.

So why handicap yourself?  

Personally, I prefer a 26" barrel and save the weight from the extra 2" by slimming down to a medium-heavy profile. You give up almost nothing in accuracy in a good barrel, and unless you are sustaining a very high rate of  fire, the heavy profile is not needed.





 

I shoot an 18" 308, and it gets to 1000yd just fine.

read the first 3 posts.  thats all you need.

but *where* does it get there? And how many shots does it take you to get *there*?

Turning it into a tac rig implies it might get humped on your shoulder. So again i say 20"

Once upon a time, long barrels were the expected norm for accuracy with rifles, but that just stemmed from the longer site radius it afforded with open sights.

These days it just comes down to the ability to run a heavier pill as fast as possible to flatten out the trajectory.

That's correct only in the sense of a designated marksman rifle where the engagement range is going to be 400m or less and where precision accuracy is not really needed for a minute of man target in a small unit engagement.

At longer ranges, where hold over is still required no matter how fast you push even a VLD bullet, and where the dispersion from a barrel with less than stellar accuracy means a miss, the idea kinda runs off the rails.

But it does speak to the need to firmly identify what you want a particular rifle to do. What will be ideal in one role, may be unsuitable in another role, and a rifle that makes a good compromise for both roles will most likely be less than optimum in either of the roles.  At that point you have to make some decisions based on your priorities and what you can live with.

I have owned more than one .308 rifle, with sub- 20" barrels, as well as my share of precision rifles with longer barrels as well. Shorter does NOT mean less accurate, as I have a 16", which is normally sub MOA with it's preferred loads. Velocity loss is not so severe as many think. For hunting applications, I prefer the shorter barrel for maneuverability in the thick stuff. I have also seen sub-20" barrels place hits on gongs at 1000 yds, though usually as a stunt, and not in any serious role where consistent hits at that range are required. In fact, when Ruger was developing their Gunsite Scout Rifle, their test marksman placed shots at 1000 yds, though the number of required shots, was not mentioned. It was also not stated if it was "walked onto" the target, or effectively dialed up, and accurately placed.

There is also a number of law enforcement, and special purpose sniper rifles, which feature 20" or less barrels. Some are marketed for more covert type use, and they are designed for the purposes of ease of carry. But such "urban" sniper rifles, as used by law enforcement, also generally see use, at ranges under 200 yds, though longer ranges are still possible. Shorter barrels are stiffer by nature, than their longer counterparts, which lends to accuracy.

Here is an article on barrel length on precision rifles, which lends credence to the better accuracy associated with a 20" barrel vs. the longer 24" barrel. It makes some excellent points, and is worth a few minutes of reading. Barrel Length And The Precision Rifle

For true long range usage, the general consensus, is to provide the most velocity feasible, to aid in maintaining a longer supersonic flight time. The quoted 1200 yd figure is more than optimistic, for a 308. Even though a record shot by a sniper was at 1200 yds, it is a rare occurrence, and only feasible with perfect factors and conditions. Even with the best projectiles selected, this range will be the exception, rather than the norm. If you are seeking a rifle/ cartridge combination for frequent use at over 1000 yds, you will probably wish to step up to a 300 Win Mag. Even at 1000 yds, you will want to take advantage of all of the velocity you can possibly get if you decide on the 308, which will mean at least a 24" tube, with a 26" tube being the best choice. Also bear in mind, that with the magnum cartridges, also comes greater barrel wear, as compared to the 308. There is also other cartridge choices, obviously, than the 300 WM, in the likes of the 300 RUM, 30-378 WBY, and several wildcats. Some would also recommend the 300 WSM, as it is an accurate round, and performs well at 1000 yds in the right setup. But all in all, it is hard to beat the 300 WM, provided you can accept it's disadvantages of higher costs, reduced barrel life, and greater recoil.

Also a factor worth considering, is what game you intend on pursuing. If you plan on taking long range shots, at elk-sized game, ethics aside, you will probably wish for greater terminal performance than that of the 308. The 308 will surely kill it, and it would be better to hunt with a 308 you can shoot accurately, than a 300 WM  you are only moderately proficient with.

If however, you plan on keeping shots less than 800 yds, then a 20" barrel is a fine choice. Just remember ammunition, quality of the barrel/ firearm, quality of the optic, environmental conditions and your personal skill-set all determine the weapons effectiveness. But again, these are only my opinions, and YMMV.

-PC-

I am going to have to respectfully disagree, kind sir.

Three weeks ago, I was reaching out to 1000 on a man-size silohuetter with a 20 inch SuperSASS with a 10x Super Sniper.

Again it depends on the purpose.  I can reach out to 1000 yards with a .45-70 Sharps given enough sighters, but I am not going to advocate that it is a 1000 yard rifle by any means, let alone a sniper rifle. The thing people seem to forget is that he difference between a target rifle and a sniper rifle is that a sniper rifle can deliver a high probability of a first round hit.

The .308 is already well past its effective range at 1000 yards and is dropping like a stone, which makes an enormous difference when you are dealing with something other than a known distance and a number of sighting shots to walk onto the target.  For example the difference in sight adjustment between 975 yards and 1000 yards is going to be on the order of 2 MOA and about 2 and half feet difference in drop. That's the difference between a "hit" and a "miss" even on a torso sized target, and if all you've got is one shot, the odds are you won't want a .308, and definitely not one handicapped with a 20" barrel and 80 fps of lost velocity.

In that regard demonstrating it can be done with a 20" barrel does not in anyway mean it's practical or optimum.  800 yards is plenty far for a .308 under real world conditions, even with the extra 80 fps or so you get with a 24" versus a 20" barrel, so implying a 20" .308 is a 1000 yard weapon in the real world is just not consistent with the observed performance of .308 caliber sniper rifles over the last 40 years.

I take it you understand that people have been shooting 308 at 1000yds in competition since like 1964 or earlier....It might not be the  " Best " sniper round for 1000 but it will get there just fine if you do your part.

Getting  a first shot in the 9 ring which is 20" isn't hard even with iron sights.

This has be one of the dumbest things I have ever read.....

The thing people seem to forget is that he difference between a target rifle and a sniper rifle is that a sniper rifle can deliver a high probability of a first round hit.

Soooooooooooooo, the fact that I can consistently hit a steel target at 1000 yards as long as I do my part is all wiped out by your statement?

So, which is my SuperSASS, a target rifle or a sniper rifle?

Keep in mind the purpose and the trials for which it was originally designed and submitted.

I also have a 24 inch 10T.  Does that meet your approval?

Thanks for illustrating my point even if you don't understand it.

Yes, you can hit a target at 1000 yards with a .308, even with iron sights and that's not a surprise as in 1000 yard prone matches iron sight scores are usually not much lower than telescopic sight scores. Of course if you look father back you'll find people hitting 1000 yard targets with cartridges like the .45-70, 45-90 and .45-110, all of which are no where near as flat shooting as a .308, thus using a more extreme ballistic example.  However under those target shooting conditions you have:

1) a known distance (1000 yards); and  

2) you have multiple sighting shots to get a round on target.

Once you have accomplished that, I'd fully expect you to keep putting rounds on target, assuming favorable wind conditions and/or requisite skill in reading the wind.  

Even if who ever surveyed the range got it wrong, and you are *only* 975 yards away, or slightly long at 1025 yards, you'll still get on target after a few (or several) sighting rounds.

However, in a field situation where you do not have the luxury of either a known distance or several sighting shots, the probability of a first round hit with a .308 is lower than it would be with a round better suited to the task, and again, using a 20" barrel just adds additional handicap on top of that.

So again, your personal experiences and convenient dismissal of the limitations aside, it really matters how the OP wants to use the rifle, and he's been pretty clear about that:

1) most of his use will be off a bench

This implies known distance and plenty of sighter shots, so 20" is a non problem.  However, a 24" barrel is also a non problem as he's carrying it from his vehicle to the bench.  When you consider both the pros and cons,  with a 20" barrel he'd be trading ballistic performance for nothing.

2) He anticipates occasional use on varmints

1000 yard prairie dogs are not going to happen with any degree of consistency, so we're talking engaging targets well inside the 800m effective range of the .308 - enough less that a 20" barrel would still work, even if it's still 80 fps slow. However it also implies a fixed shooting position where carrying 4 extra inches of barrel is a non issue, but also a large number of shots and relatively high rates of sustained fire (on a decent dog town) - a situation where the extra mass and area of an additional 4" of barrel will aid cooling.  And, bucking wind out west generally leaves me wanting a little more ballistic advantage, not less.  Just personal preference here, but given a choice between identical tactical rifles with 20" or 24" barrels, I'll take the 24" barrel every time in this situation.  Your judgment and preferences may vary.

3) He also mentions hunting.

He is not clear on what he will be hunting or where.  If it's in woods or brush where 4" of extra barrel is a potential issue, then it's also most likely shorter range hunting where a 20" barrel will not be a handicap.  If he's hunting open country in the big flat states out west, then 4" of extra barrel length is not an issue, but an extra 80 fps would be a real advantage as you are once again in a situation where the distance and wind is not known with 100% accuracy and the first shot PK is important.

Finally, the OP mentions he has two tactical rifles and wants to set them up for tactical purposes.  That is not the same as setting them up to shoot larger steel plates or targets on a 1000 yd known distance range.  

From that I infer that a higher probability of a first shot hit at longer ranges is important, and that argues for the longer barrel length.  Now, the OP's view of "tactical" may be different, but I'd prefer to give him all the pros and cons and let him decide rather than just state a personal preference, or give a single case study as an example without fully considering the context and without applying any critical thought to how well it may or may not generalize to other shooting situations.

nvm

Reasonable range is in the eye of the shooter... & specifially what you are shooting!
For shooting extreme long range steel matches out here (out to 2,000 yds.- can you even see that far in VA??), I will agree that the .308 with RL17 & a 208 Amax starts falling apart north of 1400, but certainly not at over 800!
Incidently, the 21-3/4" is from the "Warehouse" boys in TX from a few years ago.. They regularly shot in the .0s" .....

I agree with the relative range comment.

I transferred here 5 years ago and now work in DC/NOVA only two days a week and spend the rest of the week and weekend at "home" in NC, if not doing fieldwork.  In both states I've noted that 1) shooters seem to over estimate range by about 100%, and fields with ranges over 500-600 yards are not all that common in many parts of those states.  

But I transferred here from my home state of SD and 2,000 yards is just normal social distance there.

- With my 175gr Match Load, I get get an extra 150 FPS out of a 24" barrel compared to my 20" .308

- We are talking 2700fps vs. 2550 fps.  (24" vs. 20"), which is about a 5 MOA difference in drop at 1000 yards (about 50" difference in bullet drop at 1000 yards)

- 20" and 2550fps is plenty good enough for 1000 yards as the bullet is still supersonic.  In my neck of the woods, 20" is even good for 1200 yards.  

- However when engaging the bad paper at 1000-1100 yards, every little bit helps, the flatter trajectory will always be the more accurate trajectory  (5 MOA difference in drop)

- If you are shooting off a bipod (bench or prone) and not carrying your rifle around, I would go 24".  That extra help, and extra 150 fps does not cost you extra!  

- If you have to carry your rifle around, and like to shoot different position, I would go 20".


The Costanza .308 Family

GeorgeCostanza,
    Nice group photo there! I can never get mine to sit still long enough for family photos. So is a 7.62mm Katana classified as a DD or an AOW? J/K I would be interested in seeing the common crest they all seem to have on them though.

-PC-

LOL, George, do you use the katana to cut camo for your hide?

Hi everyone. I work for a manufacturer who builds both hunting and tactical rifles. We have tested our 308s with 168 Black Hills. The 20" and 24" rifles both using Schenider P5 rifled barrels in 1/11 twist were only 55 fps different. If we DO get an order for a 24", everyone is suprized. As far as accuracy is concerned, I shot one of our new products what has a 12.5inch barrel with a 1/8 twist using an Elite Iron Suppressor. I had no trouble hitting steel at 1,000 yards using 178gr Hornady Supersonic Match ammo. It only came out @2350 FPS. Yet was a predictable as any other gun we build. We have our owners come to our free for owners shooting schools who have no trouble getting on from 1.200 to 1,400 yards with our 308s. Question is, we know our guns are good. It all comes down to the shooter. How lethal is a 308 at those distances? Don't know anyone who will volunteer to find out. But, if you need to go that far, get a 300 WM. We shoot 1,800 yrds all day long with them. The new 208gr Hornady ammo is magic at that distance. Need to go further? We have customers shoot 2,300 yards with our 338 Lapuas! Need more? We make a 50BMG and a new long distance 416 chambered gun that we think will go for 3,000 yards.

Interesting. Thanks for the info.

What twist barrel?  If 1/10 I vote 20"

The Katana is Airsoft, not real

The common crest they all share is the crest for "Commitment to Excellence".  

What were your exact chrono readings?  

Did you use ammo from the same lot?

55fps gain for 4" is awfully low and I don't think is a very good gauge.   I have chrono many a barrels, 16", 18", 20", and 24" with my custom loads, and I find that 125-150 FPS difference is more the norm.  

That Hello Kitty shirt in the pic is real.

Two years ago I had one of my 24" Rem700 cut down to 20" (to serve as a suppressor host).  My usual target load is 45gr of Varget under a 168gr SMK and averaged 2742fps (10 shots fired over my F1 chrony, 10' from muzzle)

After being cut down to 20" later that day, the same load averaged 2683fps without the suppressor (again, 10 shots at 10').   So, I lost 59fps for that particular load.   The barrel is a Krieger 1:11" twist.  And my groups at 600, 800 and 1000 haven't suffered a bit.  

Interesting.  So the same barrel cut down only lost 59 fps, that's not much of a loss at all, and your groups should not suffer much at all.  

Yep, I was expecting to lose at least 100fps since I typically get ~50fps more velocity from that load in a 26" 1:11 barrel compared to my 24" guns.  I guess that 20"-24" range is a sweet spot for the Varget and 168gr SMK in that barrel.  

Of course, different barrels with different loads may show very different results.  You never know until you try.

I use 175gr SMK, the 168gr are really meant to be used for 300 yard comps, but I have found they do work well to 800.  Problem with the 168gr is the boat-tail on them is too short so they do not fly as nice as the 175gr SMK.