I'm new to precision shooting and I've been listening to the podcast trying to wrap my head around alot of info. I keep hearing lighter bullets with a faster twist is a good thing. Does that idea still hold true for a 308? Say a 20" 8 twist gas gun running 110 grain Hornady tap. Box says 3125 fps which is about 500 more than most other heavier 308 loads. Do you think this is something worth doing or am I going the wrong direction completely?
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8 twist 308 gas gun question
- Thread starter boon762
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You have to use the right tool for the job, depends on what you are trying to accomplish?
1/8 twist is a touch fast for .308
Now I don’t know that there is technically any significant downside to being “too fast “......within reason
But .308s will generally stabilize between 1/10 through 1/12 twists
The heavier(really the longer) the bullet is, the faster the twist needed to stabilize it.
110gr being really light for .308..... you can easily stabilize that in a 1/12 twist barrel and that would still be considered “too fast” for that weight projectile.
Although generally you will get a better BC with heavier bullets..... so if you wanted to run a 1/8 twist barrel.....you could safely run 200-220gr bullets provided you single load, as they likely will be too long to fit in a magazine
Now I don’t know that there is technically any significant downside to being “too fast “......within reason
But .308s will generally stabilize between 1/10 through 1/12 twists
The heavier(really the longer) the bullet is, the faster the twist needed to stabilize it.
110gr being really light for .308..... you can easily stabilize that in a 1/12 twist barrel and that would still be considered “too fast” for that weight projectile.
Although generally you will get a better BC with heavier bullets..... so if you wanted to run a 1/8 twist barrel.....you could safely run 200-220gr bullets provided you single load, as they likely will be too long to fit in a magazine
Thanks for the help guys. I bought 2 barrels but settled on the 18" 1/10 after more research and the last comment made me get a fuzzy feeling about it. I wont be reloading yet and by the time I do I'll be going to a 6 ot 6.5 barrel and reload for that. Now I just need a scope for and I'll be able to get out and shoot it.
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I have a 1:8 twist 16” barrel on a .308 gas gun, I mainly shoot 175gr, shoots good. I have also had good results with the same twist rate on a 14.5” bolt gun, barrels longer than 18” I stick with 1:10 twist though.The idea behind the fast twist rate on shorter length barrels is it helps keep the bullets path more predictable at extended distances. ( Since you are giving up muzzle velocity with the shorter barrel that extra spin keeps the round more stable in the transonic range then a slower twist rate would.)
As Old Salt said, you also want a faster twist for heavier bullets, not a slower one, you had it backwards. You will also have a higher muzzle velocity with lighter rounds, that’s why you see the 500fps difference.
Never trust what the box says.
As Old Salt said, you also want a faster twist for heavier bullets, not a slower one, you had it backwards. You will also have a higher muzzle velocity with lighter rounds, that’s why you see the 500fps difference.
Never trust what the box says.
