Minimul barrel length in .308 to reach 1000 yards

Andy T

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What is the minimum barrel length in a .308 bolt rifle that is necessary to reach 1000 yards using factory ammo ( most likely 168 SMK).
 

Dsparil

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Re: Minimul barrel length in .308 to reach 1000 yards

22" for 168s and you wont get as good of performance as you will out of 175s.
 

Sig685

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Re: Minimul barrel length in .308 to reach 1000 yards

I guess it all depends on what you mean by "reach 1000 yards."

I seriously doubt you will reach 1000 yards with a supersonic 168SMK out of any reasonable length barrel, say anything under 36 inches. The 168SMK is well know to tumble as it goes transonic, so if you do hit the target it will be interesting to see what the impact looks like.

There are people here who are firmly convinced that 16 or 18 inches are quite sufficient to reach 1000 yards. The only time I shoot at 1000 yards is in F-class competition and the targets are very small so I need accuracy. My .308 has a barrel longer than 18 or 20 inches.
 

deadly0311

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Re: Minimul barrel length in .308 to reach 1000 yards

have you ever seen the video of LL shooting his Gladius out to 1000? Thats an 18 inch barrel and he consistently hits steel out that far, guess its some video trickery, cuz it wont get it done right???
 

rijndael

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    Re: Minimul barrel length in .308 to reach 1000 yards

    It depends on your area. In my neck of the woods, sea level, I can't use 168 SMKs at 1K and get consistent (accurate) results. FWIW - I have a 26" barrel and hand load them.

    Heck, we've even had days were the Black Hills 175s crapped out at the 1K line. That was not a bad batch either .... we had 5 shooters, at an F Class match, all having very erratic results.
     

    Sig685

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    Re: Minimul barrel length in .308 to reach 1000 yards

    Andy T had better tell us in which part of the country he intends to be shooting these 168gr SMKs at 1000 yards.
     

    GorbashUK

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    Re: Minimul barrel length in .308 to reach 1000 ya

    Nearly all barrel lengths will get a 308 bullet out to 1000yds, but its getting the bullet out to 1000yds while it is still travelling at a supersonic speed that really counts. Our Fclass TR brethern, seem to favour 155gr heads and 30 or 32 inch barrels to keep that bullet fast and avoiding wind, all the better for hitting a 5 inch V bull at 1000.
     

    clmayfield

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    Re: Minimul barrel length in .308 to reach 1000 ya

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sig685</div><div class="ubbcode-body">
    I seriously doubt you will reach 1000 yards with a supersonic 168SMK out of any reasonable length barrel, say anything under 36 inches. The 168SMK is well know to tumble as it goes transonic, so if you do hit the target it will be interesting to see what the impact looks like.
    </div></div>

    36"? Are you for real?
     

    lowlight

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    Re: Minimul barrel length in .308 to reach 1000 ya

    One thing nobody, especially the F Class guys aren't acknowledging in their explanation as to why they run the 308 the way they do, is, first and foremost "competition". 2ndly is, they dont' have to move with the rifle.

    They need to get the edge over the next shooter, so the faster they can push the bullet the better off, and more likely they are to get the edge over the competition. Especially what they are doing with the 308 and the 155gr bullet which is giving it the same ballistics as a 260 shooting a lighter bullet.

    If you want to compete against other shooters, then you have to run their race. However, its not necessary and you can successfully push a 308 for a tactical rifle with a 308 shooting stock 175gr bullets, even at sea level which is where I shot those rounds at in the video.

    I hit 5 out of 6 shots on that video on a target at 1000 yards with an 18" barrel, and then hit the 7th shot on a target which was 8.75" by 14.75"... so in width I was accurate to less than 1 MOA and in elevation I was consistent to 1.5 MOA at worst. I can do it over and over... and have done it on command for people who will argue they need more barrel.

    The accuracy out of the shorter, stiffer barrels is amazing, even in the wind, and it will hit consistently if you shoot it that way. In my rifle with factory 175gr bullets, I am getting no less than 2575fps which is more than enough, and if I really wanted to up the ante, I can shoot my factory 170gr HPS stuff which is rated around 2750fps (at 18") with a bullet with a .525 BC so do the math.

    I should note, when shooting in competition, tactical mind you, my 22" Harbinger won the 600 yard group shot shooting factory ammo in a 12MPH wind... I shot a 3.25" with a 22" 308... I bet I can do the same with an 18", and have at least hit close enough at 1000 yards on video to make it plausible.

    Don't listen to the gamers, because they are doing exactly that, gaming the 308 to act like something else in order to gain an advantage...

    although I will say, 168gr bullets don't fair so well at distance.
     

    long-shot

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    Re: Minimul barrel length in .308 to reach 1000 ya

    I think it's important to mention that not all of us can make consistent hits at 1K with an 18" .308. I'm one of them. I shoot a 22" .308 pushing 175's to just under 2700 fps and feel comfortable out to 800 yards. I shoot pretty consistent, and place in most of our local tactical matches so I'm not a beginner either.
     

    sobrbiker883

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    Re: Minimul barrel length in .308 to reach 1000 ya

    My 168 Noslers went to 1K at NorCal this year.
    My loads run 2675fps out of a 25.5" Rock at 2000ft asl.

    At Sacramento (250asl) I din't fare well at 1K, mainly out of inexperience at that distance, but a couple of my rounds during a good gust keyholed.

    I will not be using 168's at 1K again.......
     

    clmayfield

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    Re: Minimul barrel length in .308 to reach 1000 ya

    I was looking at JBM... simulators are usually suspect... but it shows a 168gr using FGMM MV's from Federal going subsonic at 950 yards. 175gr using FGMM MV's from Federal stay supersonic until past 1,000 yards (but not by much).

    I am taken aback by the 36" comment because you don't really get much appreciable velocity increase past 22" with factory loads (and I would say more like 20"). A longer barrel will get you some more flexibility in terms of powders used for the handloaders. Palma shooters go around 30", but mainly to get the increased sight radius. I have also had conversations with Mike Miller who runs a 30" for F/TR. He can use a much slower powder that way and push his load to the max to get every ounce of velocity out. He also uses 155gr bullets... he has done the math and he gets less drift with the lighter bullet at a higher MV.

    The problem that you have is that at some point past the marginal increases you get with a longer barrel, the velocity actually starts to decrease with the longer barrel. Obviously, it depends on what you are running, but 36" sounds a bit high. But I guess the comment was pointed more towards the projectile in question and less towards barrel length.
     

    Sig685

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    Re: Minimul barrel length in .308 to reach 1000 ya

    The 168gr SMK tumbles when it goes transonic, that is a well known fact. That bullet is very accurate out to 600 yards but it's BC simply does not allow it to get to 1000 yards supersonically unless you push the heck out of it and that will be with a long barrel and lots of slow powder. I was exagerating, but not by much when I talked about a 36inch barrel.

    Just for the record, I am using 180gr bullets at 2840FPS out of my 32 inch tube, (yes, I handload.) Lowlight is absolutely right in that I am not moving with the rifle and I also was not saying that someone cannot be accurate with a short barrel. I just said that it was not possible to be accurate at 1000 yard, WITH a short barrel and WITH 168gr SMK. Switching to 175gr or to Noslers or to 155gr bullets and everything changes.
     

    Andy T

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    Re: Minimul barrel length in .308 to reach 1000 ya

    Thank you for the replies. The need to reach 1000 is because I want to take a class next year where we shoot up to 1000 yards. However, I don't expect 1000 yards to be the majority of shooting.
    I also want it to be handy since I am looking for more of a tactical - as much as this word gets abused - rifle.
    Definitely not a Palma gun.
    I am also not dead set on 168gr. It's just what I used in my previous rifle. As long as I can get factory ammo, it will be good to go.
     

    abersfelderami

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    Re: Minimul barrel length in .308 to reach 1000 ya

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Carter Mayfield</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sig685</div><div class="ubbcode-body">
    I seriously doubt you will reach 1000 yards with a supersonic 168SMK out of any reasonable length barrel, say anything under 36 inches. The 168SMK is well know to tumble as it goes transonic, so if you do hit the target it will be interesting to see what the impact looks like.
    </div></div>

    36"? Are you for real? </div></div>

    When game warden ask "Do you have haunting licence?" You cann say " I'm fishing, Sir."
     

    OutRider

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    Re: Minimul barrel length in .308 to reach 1000 ya

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Carter Mayfield</div><div class="ubbcode-body">I was looking at JBM... simulators are usually suspect... but it shows a 168gr using FGMM MV's from Federal going subsonic at 950 yards. 175gr using FGMM MV's from Federal stay supersonic until past 1,000 yards (but not by much).

    I am taken aback by the 36" comment because you don't really get much appreciable velocity increase past 22" with factory loads (and I would say more like 20"). A longer barrel will get you some more flexibility in terms of powders used for the handloaders. Palma shooters go around 30", but mainly to get the increased sight radius. I have also had conversations with Mike Miller who runs a 30" for F/TR. He can use a much slower powder that way and push his load to the max to get every ounce of velocity out. He also uses 155gr bullets... he has done the math and he gets less drift with the lighter bullet at a higher MV.

    The problem that you have is that at some point past the marginal increases you get with a longer barrel, the velocity actually starts to decrease with the longer barrel. Obviously, it depends on what you are running, but 36" sounds a bit high. But I guess the comment was pointed more towards the projectile in question and less towards barrel length. </div></div>

    I was surpised to learn that the difference in velocity betwixt a 20" tube and a 26" tube was said to be aproximently 100 fps in a .338 Lapua rifle I was researching. This seemed to defy logic, and the builder said it came as something of a surpise to him as well, but stated these numbers as a verified fact.
     

    Sig685

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    Re: Minimul barrel length in .308 to reach 1000 ya

    Ghosts need a license?

    OutRider, what aspect of the difference in velocity seems to defy logic? I actually think 100FPS is on the low side, the .338 Lapua has a huge powder load and a 20 inch barrels wastes a lot of it.
     

    ewoaf

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    Re: Minimul barrel length in .308 to reach 1000 ya

    andy needs to (not only relay more info, ie elevation) but to also look into something like the Amax if he likes 168's not only do they have slightly higher BC, but are also slightly cheaper. I and a few others here love them per past threads (look them up)
    and yes they are easier to get to 1k super sonic, but then so are 175's 155's etc...just sayin.
     

    Slinky001

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    Re: Minimul barrel length in .308 to reach 1000 ya

    If you want to use a lighter bullet try a 155 Lapua at 1000, it gives nice results. Skip the 168!

    On average a 30" barrel with a load of 46.0 of Varget and the Lapua mentioned above will get you to approx. 3000 fps. Do the math backwards from there to get a ballpark figure.

    This is not exact, but assume you will lose 20-25fps for every inch that you take off a barrel.
     

    LoneWolfUSMC

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    Re: Minimul barrel length in .308 to reach 1000 ya

    My 26" barrel gets the 155 Scenars to almost 3000 with 47gr of RE15.

    They smoke out there nicely. I need to pickup some more. I usually shoot 168 SMK's sine that is what I am issued at work, but the 155's are nice.