308 barrel length

David78b

Well-Known Member
What is the best barrel length for a 308. Is 20 inch a good length or would 22 inch be better. What twist rate would be good for the coming non lead ammunition. Thanks
 
I guess it depends on what you are using it for. Mine is 20" for a stalking rifle and I'm very pleased with it. It's sending a 150gr gameking at 2959fps with 46gr N140. It's very accurate as well
 
I guess it depends on what you are using it for. Mine is 20" for a stalking rifle and I'm very pleased with it. It's sending a 150gr gameking at 2959fps with 46gr N140. It's very accurate as well
That's some velocity you are getting from that load, I would have expected about 300fps slower.
 
That's some velocity you are getting from that load, I would have expected about 300fps slower.
I thought so too. It's not max load either. I put a stainless baffle in my dpt and it made it increase to this.
I checked my chrono to my friends and it checked out. I put it down to the sassen barrel. I'd love to know why.
I have a 6.5CM and see people's speeds with my bullet weight etc and I'm a lot slower. I just load for the accuracy really.
 
I thought so too. It's not max load either. I put a stainless baffle in my dpt and it made it increase to this.
I checked my chrono to my friends and it checked out. I put it down to the sassen barrel. I'd love to know why.
I have a 6.5CM and see people's speeds with my bullet weight etc and I'm a lot slower. I just load for the accuracy really.
Interesting, I've got an M12 Impact in .308 with 20" barrel and DPT mod. I use 150g Gamekings but haven't chronographed my current load, just calibrated by shooting at different ranges. Will have to borrow a chronograph and see what I'm getting.
 
Interesting, I've got an M12 Impact in .308 with 20" barrel and DPT mod. I use 150g Gamekings but haven't chronographed my current load, just calibrated by shooting at different ranges. Will have to borrow a chronograph and see what I'm getting.
I will PM you to save clogging the thread with chat
 
Unlike the .243, the .308 is a chambering that doesn't lose much oomph with short barrels. For example, I have an 18 inch barreled Sauer 202 in .308 that perform similarly with 180gr Sierra Matchkings over 900yds at Stickledown to my 24 inch AI. It is so handy and light to carry that I would recommend it.
 
I also agree that 308 performs well with a short barrel, especially if you reload. A heavy end of barrel moderator restores the balance and will give you years of use.
 
“Best” is entirely dependent on the intended application.

For me, having a short-as-possible moderated barrel is the main reason to opt for the .308 chambering — at least in typical hunting-oriented builds.

20” is more than enough even for target shooting, and 18” or even 16” would be plenty in most field applications. I wouldn’t bother with 22”, with the possible exception of cutting down on noise and muzzle blast with an unmoderated rifle.
 
I guess it depends on what you are using it for. Mine is 20" for a stalking rifle and I'm very pleased with it. It's sending a 150gr gameking at 2959fps with 46gr N140. It's very accurate as well
Hmm I'd check the chronograph again - that's not far from 150fps more than Vhit reckon they get with 47.1gr in a 24in barrel! Prepared to be corrected, but would think it rare to exceed max book speeds with less powder and barrel 🤷‍♂️ Perhaps a tight bore? Also pretty sure the mod won't influence velocity.

Same bullet with 44gr N140 in a 22in Schultz barrel gives me 2,650fps (measured with a MagnetoSpeed). With a short mod, I find that pretty versatile and not unwieldy (but then I don't typically hunt in the woods).
 
I have an 18" .308 straight pull that keeps 168gr TMKs inside the V at 900y on stickledown... but if you want to get out much further than that I find things tend to go subsonic. I haven't put more time in to work out a load for 1000y+ since I'd probably need to go much heavier and single load.

My next .308 will be a 26" barrel for longer ranges, TR shooters often have silly long barrels but that also helps the sight radius.
Depends what you are using it for, really.
 
Hmm I'd check the chronograph again - that's not far from 150fps more than Vhit reckon they get with 47.1gr in a 24in barrel! Prepared to be corrected, but would think it rare to exceed max book speeds with less powder and barrel 🤷‍♂️ Perhaps a tight bore? Also pretty sure the mod won't influence velocity.

Same bullet with 44gr N140 in a 22in Schultz barrel gives me 2,650fps (measured with a MagnetoSpeed). With a short mod, I find that pretty versatile and not unwieldy (but then I don't typically hunt in the woods).
I completely agree with you. I know it does 2808 FPS before I fitted the SS baffle. I have shot this for 12months and it's been accurate with me using strelok.
Obviously I will test this new speed also.
Or shoot across another chrono if I get chance. I did try my chrono when new last year to my friends. They were within a few feet.
I would agree with you. I never get near the book speeds as my barrels are all shorter . I would expect 100fps less than they say.
My SST load is a lot slower than this. 2685fps with 43gr n140. Which seems more realistic.
It's a job in progress and I will check when I get chance.
 
I thought so too. It's not max load either. I put a stainless baffle in my dpt and it made it increase to this.
I checked my chrono to my friends and it checked out. I put it down to the sassen barrel. I'd love to know why.
I have a 6.5CM and see people's speeds with my bullet weight etc and I'm a lot slower. I just load for the accuracy really.
How would a stainless baffle increase the velocity of the bullet after it has left the barrel?
 
I thought so too. It's not max load either. I put a stainless baffle in my dpt and it made it increase to this.
I checked my chrono to my friends and it checked out. I put it down to the sassen barrel. I'd love to know why.
I have a 6.5CM and see people's speeds with my bullet weight etc and I'm a lot slower. I just load for the accuracy really.
Sassen can be 200 fps up due to the lapping done. a moderator no matter how designed should have no discernable influence on velocity ( other than muzzle blast reduction through the chrono)
 
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