308 win barrel length and twist rate?

I went with a McGowan 18" 1:9 twist on a tikka. It shoots 200&190 subs excellent to 150 yards. 150 Norma box ammo and 165 gr with varget just as well. I'm going to try 125 nosler/sierra with n140 too.
 
I shoot the 308s using 15,14,12,11, and 10 twists.

Chamber(throat, freebore) dimensions are important when you expect bug hole accuracy.

10 twist is plenty for bullets up to 190g, if you want to go 200s, hedge your bet by going 9.

I am in the camp of picking the twist, throat, and freebore for your intended bullets to be used, then plan on Great success.
 
So Sam, what did you decide? 🤔
Haven't decided yet looking at other prefit barrels in my budget. Still kind of wanting to try a 1/8 twist but 1/10 or 1/9 would probably better suit my needs. My other 308 is 1/12 twist so I though about doing this one 1/8 to load heavies and use the other 308 for the lighter bullets
 
What is your intention for the heavy bullets?
You should also look at the prices of heavy vs. light bullets, plus availability.
The heavier they are the more they cost.
If it's for punching holes in paper, deer and varmints, light to medium weight bullets do that just fine.......just saying.
 
What is your intention for the heavy bullets?
You should also look at the prices of heavy vs. light bullets, plus availability.
The heavier they are the more they cost.
If it's for punching holes in paper, deer and varmints, light to medium weight bullets do that just fine.......just saying.
That is true. I do already have an around 500 185s and 400 210s that I bought for my 300 win mag but i ended up settling on 166 hammer hunter bullets for it due to I use it only for hunting. As far as that all other bullets I have 200 or more of is 178s to 150s as of right now. I believe I'll try and just fine a 1/10 twist prefit if I can find one in my budget or save up some more
 
I run a 1-8 18" 308. I got it because my thinking was it would work out well for a shorter barrel. It does shoot 165-168 gr. copper and traditional really well and have even taken it out to 1k yards no problem, but it doesn't like the 150s or 175s so you'll just have to find a weight it likes you can't force it to like one.
 
If you're going to use heavy monos then an 8 might be the way to go, but if not a 10 is hard to beat even at 210's for hunting bullets. For long heavy bc bullets going 9 is safe. Here's another thought, what is your mag length and what type of mags will fit in this gun? If you can use AR10 mags, go with LaRue or ASC as you can get up to 2.865"ish. Pmag gen3 m118 mags only go to 2.830", but the gen2's I think have the same length? I have 2 m118 chambered 308's w/11 twist from CBI and couldn't be happier!
 
I'm looking at re barreling a rifle I have and want to stay with 308 win. The barrel on it now is 20 inch's 1/12 twist (from what I can tell) I'm wanting to go with a little longer barrel and fast twist rate. I've been looking at outlier barrels as they have a sale on their prefit barrels. The only 308 caliber barrels they offer is 1/8 twist from 18 to 26 inch's. I was thinking of getting a 22 inch barrel with the 1/8 twist rate would I be hurting my self in any way by doing so or should I go back with 20 inch or go longer than 22 inches? Also would 1/8 twist be to fast for lighter bullets? I've heard of over twisting bullets but I've never experienced this or what can happen by doing so? Any help is greatly appreciated thanks. God bless
I shoot the 168VLDs, 208 A-Max and 210 VLDs in my 110"T : Savage 22" Weather Warrior all with IMR8201XBR. ALL shoot well
 
I shoot the 168VLDs, 208 A-Max and 210 VLDs in my 110"T : Savage 22" Weather Warr & Tikka 308s.
 
To answer your original question…1:10. Other than subsonic loads, I find myself scratching my head when folks shoot anything heavier than a 175 grain projectile out of a .308. My question is why???

Going over 175 grains in a .30 cal equals 30-06 or larger to me anyways. If you're thinking big monos, out of a .308, don't. Speed is the name of the game for monos.
 
1:10 is all you need. But 1:8 will not hurt anything. We shoot the 215 grain Berger Hybrid Target bullet out of a .308 for testing each shift of production day in and day out. The normal test barrels are 1:10 26" but we also test 1:8 for specific contracts. Even down to our 115 grain flat base match bullet. It will still shoot sub .5 MOA at 300 meters.
There is no such thing as over stabilized but you can increase friction to a point the bulle gets too hot and spins apart, that won't happen at .308 velocities.
 
I'm not saying everyone is wrong, but my experience on fast twist rates doesn't reflect what the majority say. Example, I have a 16" .308 with a 1:7 twist. I have shot 110 v max and 115 Lehigh defense super sonics up to 220 gr subsonic and they all just flat out shoot. I built this rifle for being extremely light, short and handy. Yes it is a little slower being a 16" gun, but it's a 400 yard rig, I'll never be shooting it farther. So, 1:8 is fine, however I'd maybe look real hard at some info on outlier barrels before jumping in on them
 
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