308 Win Barrel Length

pyscodog

Active member
My 700 has a 26" barrel and was considering shortening it some. I know it effects velocity but I did a search and read an article where sometimes it doesn't effect it like you think it would.

The testing was with 150 grain factory ammo.

24"-2745 FPS
23"-2732
22"-2686
21'-2774
20'-2732

The author said he had seen velocity rise with a shorter barrel but really couldn't explain it other than maybe harmonics of the barrel.

I just want to make mine a little lighter and easier to maneuver. I know cutting 5-6 inch's off the barrel is minimal as far as weight but it won't hurt. But I do think it will be easier to maneuver and look better also. Probably have it threaded at the same time.
 
I reload for all my guns. I have a Rem 700 SPS .308 that had a 26" barrel with 1/12 twist which I cut down to 16" and threaded to run a Ti can (10" length).

Using the same exact load (165gr SST, Varget and Fed 210 primer).

26" velocities = 2630 fps
16" velocities = 2506 fps

I also have a Rem 700 .308 with a 20" barrel. For hunting suppressed I like the 16" barrel, but if I was not going to hunt using a suppressor than the 20" feels much more balanced to me.

 
The 308 Win isn't a real speed demon to begin with. The 308 bore dia. to amount of powder it burns ratio is pretty mild so it should be one of those cartridges that isn't really all that handicapped with a shorter barrel.

Generally, it's the overbore cartridges that are more affected with velocity fall off as the barrel gets shorter.

Will it lose velocity going from 26 to 20, sure, but I'd be surprised if it was much over 100fps and it wouldn't surprise me to hear you found it consistently shot not only better but was easier to work up a load for.

I've had numerous centerfire barrels shortened up and they all lost velocity but ever single one of them at the least shot as well as it did before and some even shot better.
 
Kinda depends upon the rifle and it's projected use. A heavy barrel varmint rifle that will be shot from a bench or solid rest and length and girth don't matter much. A packing rifle that may take quick shots in short to medium range hunting situations demands a better balanced and quicker handling rifle. In that case I like 20" - 22" in a sporter configuration. I do not care for the super stubby 16" - 18" barrels.
 
I'm going to chronograph my loads this week with the 26" barrel and see where I'm at. Then decide if and how much I want to cut it back.
 
Lopping off 4 inches isn't going to change a whole lot and 22 inches is a good length. I have bolt guns with tubes from 18 to 30 and one of my favorites rifles wears a 22 inch pipe.

I wouldn't worry to much about the velocity, it's a 308, nobody shoots those things and cares much about how fast or slow they shoot.
 
I shoot mostly 168 grain bullets. Mainly because I have a lot of them. With that heavy of a bullet there isn't blistering speed anyway.
 
I had a Savage 99 in 308 with a 16 1/2" barrel that was about the sweetest still hunting rifle for the big woods of northern MN and WI. It would sling 180gr RNs like it was made just for them, never had to shoot one twice. I loaned it to my little nephew and when he killed his first deer with it, I gave it to him. He's still killing deer with it and that's going on 20yrs now. My niece is a budding gunsmith and she refinished it for him, looks like new now.
 
Last edited:
Originally Posted By: pyscodogI shoot mostly 168 grain bullets. Mainly because I have a lot of them. With that heavy of a bullet there isn't blistering speed anyway.

if youre gonna be hunting 400 yds or under it probably wont effect you very much, other than redoing your click charts a bit on the longer distances.

thats the kicker though - make your click/holdover charts for whatever you're doing, and then pick a bullet that operates inside your intended velocity ranges for the distances you'll be hunting at.


if its for target use, then meh... find an accurate load, know your clicks/reticle and rock it.
 
Originally Posted By: Zastava223rem.308 will generally peak at 20".

This really isn’t true. Sure, most guys don’t ask anything of the 308win which can’t be solved by a 20” barrel, but it’s false to say the 308 “peaks” at 20”. We’ve seen far too many guys shooting 30” Palma rifles and outrunning 20, 24”, and 26” barrels for too many years, so we knew this wasn’t true on its face - BUT - MDT recently dropped a video in which they produced a 69” barrel 308win, and it was still not quite flatlining at 69”. They showed a nearly linear velocity gain per inch from 19” clear up to 40”, where the gain began slowing, but still remained accelerating through 60”, and slightly so to 69”. Although it was only around 6% velocity gain, 13% KE gain, if you think about that implication - meaning around 6.5 grains of powder loaded into a 308win case simply aren’t doing anything at all, it doesn’t make me feel good saying “308win peaks in 20” barrels” any more.

[video:youtube][/video]

Also worth considering - while 5-6” of Sporter barrel doesn’t seem like much weight, it DOES change the handling of the rifle considerably. 6” of Sporter barrel will weigh around 10oz, so it’s actually pretty substantial on the overall rifle weight, but even more important, those 10oz are coming from the longest potential lever arm. Muzzle weight pulls the balance point of the rifle forward like crazy, so when you cut 10oz from the barrel, it’s like cutting TWICE as much weight from the forend - meaning on a wood stocked rifle, it’s like cutting the forend completely off at the action screw. It might move the balance point of the rifle 2” or more. This means the rifle will feel much faster handling, putting the center of mass very close to your trigger hand, but it won’t level as well on target, and will roll upwards in recoil MUCH more than before.

But for the meager task of hunting, a 20” does just fine - and frankly, hauling a 26” barrel just to have the performance of a 308win is pretty frustrating. I don’t like the 308win in general, so I’d likely rebarrel to a 24” 7-08AI, but if I stuck with 308, I’d cut it down to 22”, or 20” and stick a can on the end. Same overall length and roughly same total weight as it is now, but with universal hearing protection - AND the option to shed over half a pound and 6” if I ever wanted.
 
Last edited:
I have multiple hunting rifles with 18 1/2-20" barrels, aside from the velocity factor, you would be surprised at how much easier they are to carry and maneuver especially with the combination of the short action and shorter barrel, and they are accurate.
 
Originally Posted By: MPFDI'm getting 2600 FPS from a 16" barrel with 168 SMK's.

That's fast from that barrel length...
 
just cut it to 18" and use a little faster burning powder and then drop down to a 150 Power Hammer Bullet from Hammer Bullets in Montana run your can and be a very happy camper and that is a fantastic bullet not picky about coal very accurate and fast to find a load very little load work. I came up with a good load in 9 rounds
 
Originally Posted By: GCOriginally Posted By: MPFDI'm getting 2600 FPS from a 16" barrel with 168 SMK's.

That's fast from that barrel length...

Yeah, It's a little hot but not awful. I'm using IMR3031
 
Personally I like 20 -22" in my . 308s (I'm down to four of them now). Shorter than 20" I don't like the muzzle blast. Longer than 22" gets a lot less handy (I have one with a 24" barrel). My best shooting . 308 is an old Ruger 77 Flatbolt that has a "fast" 22" barrel. It gets a chronographed 2900 fps out of 150 grain Sierra Game Kings with 48 grians of Reloder 15. My 24" Bergara doesn't chrono any faster.
 
Most loads with the 308 use relatively faster rifle powders, not as fast, but similar to 30-30 powders. Compare that to something like the 300 win mag, which often uses slower powders.

Barrel reduction is more pronounced with the slower powders, I’m talking about % of loss with a 300 win mag compared to a 308.

My favorite rifles for still hunting usually have a 20” barrel. I can live a little on either side of that, I know 24” is to long for me, unless on a bench. I like to be in cover, average shot 50-75 yards.
 
Back
Top