.308 win, barrel length vs bullet weight

I have the latest copy of NZ Guns & Hunting in front of me, apparently the last printed issue ever!

It has an article entitled "Accuracy is all About Consistency" by Evan Honore. In this article, Honore, who sounds pretty experienced and with the .308 Win in particular, states "you need a 22-inch or longer barrel to shoot 165gr" [bullets in a .308]. Later he says "A 22-inch .308 barrel can shoot 165gr projectiles maximum, whereas a 24-inch barrel can shoot 180g" and goes on to say that the common 20-inch barrels are limited to 150g projectile max.

He doesn't really explain what he means by "shoot" nor does he give what his expectations are. I'd have to say the pictures of groups in the article are very impressive, mostly pics of groups with holes touching. So perhaps the above is based on expectations of that type of accuracy? But I've never of anyone else arguing such a critical relationship between barrel length and bullet weight.

I've owned a few .308s and have mostly used 165gr bullets (hornday SPs and SSTs mostly). A sako with a 20" barrel would put them into 25mm groups at 100m and a Howa with a 19" barrel that groups 165gr bullets into an average of around 18mm at 100m with the SP bullets - in my book that is good enough accuracy and clearly at odds with what Honore has written.

Mind you, I've never tried 180gr bullets and its been over a decade since I shoot either a deer or a target more than 100m away... so perhaps I'm not testing things hard enough to know my bullet/barrel length combo doesn't work..??

I'm sure the author is basing his statements on experience but I feel he is not giving enough info in the article to enable me to judge how he has come to his conclusions.

Now, many of you will run shorter barrels than I do, and wondering about how you get on with various weight bullets in your .308?

I run 180gr SPs out of a 20inch BLR for my bush load, sure they are not going super fast. Do I care.............. No.

I have used a 308 20" Remington LTR for many years and shoot it out to 700 yards on paper, best was 9 x bull and one just outside x bull 59 out of a possible 60 points that was a good day!

I use 155 gr Amax and find they also drop game just fine, dropped two Fallow one straight after the other standing next to each other stone dead at 500 yards across a gully, also a good day!

Tried other match projectiles which were amazingly accurate but would fail to stop a wallaby in its tracks if it made it to cover before falling over I thought I missed it, a strange day that was!

20" LTR is 2700 fps my Sako TRG22 26" was 2900 fps same load.

Scot Trail must be running 50grn projectiles in his one then...10" barrel if memory serves me correctly...and shooting animals out to 400ish....much dialup needed of course.

I think the twist rate has far more to do with it than barrel length...barrel length will help with velocity definately....guys with short barrels often drop down in weight to keep velocity up so trajectory isnt so much of a rainbow.
mine is 21" and handles everything Ive tried so far 125-200grn.

I would have thought twist rate was more important than barrel length in relation to bullet weight.
I have a 24 inch 1:12 twist and a 16.5 inch 1:8 twist. The 24 likes the 178gr eld-x, I haven't done any supersonic load development for the 16.5 yet but have shot 150 and 180gr factory ammo - not definitive but the 150 does seem to shoot better so far.
Interestingly the difference in muzzle velocity between the two rifles with the 150 factory ammo is only 135fps

Magazine writers :D

My 18in bbl 308 shoots 150 gn to 168gn pills into tiny little bug hole groups, REM factory bbl chopped to 18in

All replies are exactly what I expected.

Rather odd article really, again I'm not doubting that his opinions are based on his experience, but he needs more detail on how he reached his conclusions and probably needs to take note of what the rest of us are up to.

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Originally Posted by Dama dama

All replies are exactly what I expected.

Rather odd article really, again I'm not doubting that his opinions are based on his experience, but he needs more detail on how he reached his conclusions and probably needs to take note of what the rest of us are up to.

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It needs some context, Is he talking about benchrest shooting where they live and die by a couple of thou in group sizes or is he talking about hunting rifles?
If its the latter then no surprise it is the last edition.

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Originally Posted by veitnamcam

It needs some context, Is he talking about benchrest shooting where they live and die by a couple of thou in group sizes or is he talking about hunting rifles?
If its the latter then no surprise it is the last edition.

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He is definitely discussing hunting rifles.

Opinion masquerading as fact !

Yes, but wrapped up in a reputable publication with glossy pictures, and many, less experienced, people will take it as fact.

I recall reading a piece by, Nathan Foster. Even he (who loves long barrels) stated there was no need for a .308win to be any longer than 20", and 18 & 19" are fine too, and he prefers bullets in the 165-178gr weight range.

130's at 2950 from a 16.5" 1:8T.

Validates why i haven't brough gun and hunting magazines for 10 years !

Often flick through them in huts and it reminds me why i stopped buying them.

Same things written from the opposite direction.
Worst of all mostly hunting articles written by elite hunters with no humility and consideration of the new inexperienced want to be hunters reading them.

Lol idk how I was shooting 225 eld ms out of my 16.5 inch Bergara's before I left home.

Was reading that very same article today scratching my head in on a number of things. I guess everyone is welcome to their own opinion, his reasoning is not clearly stated but think hes based it around 2600 fps mv.
With all the different projectiles, powder combinations and superperformance ammo it's rather more complicated than that assumption could possibly be best described as very "old school".
Will need to tell my 20" Rem it shouldn't like 168's & 175's

I read the article too . . . I guess it depends a bit on perspective, I assume he is a Yank, and probably into long range target shooting (and possibly a little bit of hunting, by our NZ standards a tiny bit of hunting!).

The background to his assertions was poorly/not at all explained but I took it that he must be suggesting that shorter barrels can't get the bigger projectiles going fast enough that will ensure they are still supersonic (most target shooters hate the projectile going subsonic as they encounter self generated turbulence during the transition) at longer ranges.

I've been working up a Lithgow LA102 in 308 with a 22" barrel, and on the target range or shooting gongs it will be a liability (compared with a 28-32" full-blown F class rifle) at anything over about 1000M even though it is sufficiently accurate (to be competitive) and very consistent at shorter ranges.

However I'm not going to be bothered carrying an F Class rifle up a ridge to plink at Wallabies or goats - but I'll happily take the Lithgow.

The magazine must of been desperate for articles because some of that authors ideas are fanciful at best.

As always in ballistics and reloading, there are many variables which aren't set in stone. Different rifles, loading components, different outcomes.

Sounds like the writer has assumed a fixed twist rate that is relatively slow.

If hes basing it off like a 1/12 or more twist, then it could be true that it needs more barrel length in order to get the velocity (thus rpm) high enough to stabilise a projectile that otherwise would be borderline for the twist rate.
What the writer has written (not that iv read the article) would only be true in a barrel with a twist rate that is borderline fast enough for the heavier projecitles mentioned.

Projectile RPM (stability) is dictated by both barrel twist rate and velocity. You can get the projectile RPM up by increasing either or both

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Originally Posted by Got-ya

I run 180gr SPs out of a 20inch BLR for my bush load, sure they are not going super fast. Do I care.............. No.

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Good onya mate ,I have a BLR 308 with 15inch barrel and dpt can ,tried some Hornady Precision Hunter 178gr man they are the most accurate load I've ever used in this gun and they won't be going very fast at all from a 15 incher but certainly put deer down.

Yeah, I reckon when you go shorter barrel the 30 cal has quite a few advantages with the bigger bullets, as opposed to chopping say 6.5's. Just my opinion

I have a large pile of old American rifleman magazines from the late 50s through the early 70s. I find them a treasure trove of articles much of which seems to be regurgitated in modern magazines just discovered fact. Lisle Kilbourn in particular wrote some interesting articles on 308 when it was reasonably new. (1950s)
If I recall correctly any barrel under 16 inches gave good velocities but excessive muzzle flash and acceptable hunting accuracy. 20 inches gave higher velocity, almost no flash and better target accuracy, and 24 or 26 inches better target accuracy no flash, but the velocity peaked at 24 in.
There was some thought that with the longer barrels turbulence in the gas stream and its pressure had subsided so any venturi effect due to minute scratches in the bullet base was non existent and this helped with accuracy. 14 inches was the minimum barrel length I remember being mentioned.
Next rainy day I should really go through them and scan and index all the good articles.