twist rate for .223

From your other post, it seems you are looking for a target rifle.

If so then 1:8 is best, this will allow you to shoot the heavier .223 bullets, and this will save you considerable wind drift at longer distances
 
1:7 was developed to stabilize the looong 5.56 tracer bullet. It isn't really necessary for 80gr target bullets. If a person were to want to use 90gr. JLKs, it might make sense.
 
Light Infantry 80 grs won't work in a 1/9 at least not in my remington xcr the best bullet for long range in 1/9 is the Beger 75grVLD Varget ,Vt540 the 69 gr sierras a very good as well but only to 600 max
manitou
 
I agree. SMK 69 grs work great in a 1/9 twist.

They are not any less accurate than heavier bullets, they just have a lower BC so they don't buck the wind as well.
 
Hey guys - quick question - twist is measured in inches, right? Does 1:9 mean one complete revolution over 9" of barrel length? ie: a 12" twist means 1 rev in 12" of barrel? And the lower the number means more twist, which spins the bullet faster = better stabilization of heavy bullets?

Am I way off here?

And if so - why bother with low twist? (ie: my rem 700 in .223 has 12" ROT) -since it limits the use of heavy bullets - unless lighter (50-60gr) bullets suffer if they spin too fast.....could that be the case?
 
Yes, dbala, you are correct about twist. Fast twist is not good with light bullets as it causes the jackets to peel off. Heavier bullets only recently started becoming popular as traditional shooting revolved around using bigger calibers to get bigger bullets out to longer range. Nobody likes recoil (at least normal people) so in recent years it has become popular to use lighter calibers to go further. As well back in the day - high velocity was a big deal so twists had to be slow to get that 40-55 grain pill going fast.
 
dbala said:
And if so - why bother with low twist? (ie: my rem 700 in .223 has 12" ROT) -since it limits the use of heavy bullets - unless lighter (50-60gr) bullets suffer if they spin too fast.....could that be the case?
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Heavier bullets require a lower twist ratio, in order to achieve proper spin, and therefore accuracy. There are plenty of resources for determining the appropriate twist with the weight of bullet you use. The catch is that a lower twist ratio can cause jacket/core separation problems with lighter bullets, which will also affect accuracy. Unfortunately there is no way that I know of to determine if jacket/core separation will or will not occur. You can test different manufacturers and assuming your rifle is properly tuned, you should be able to guesstimate when jacket/core separation happens, and change manufacturers as required, until you find one you're happy with.

Remember, there really is no one "magic bullet" for all tasks.

-- Stephen
 
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