Thread: .308 win, barrel length vs bullet weight

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

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.

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.