Quote Originally Posted by sarge4318 View Post
Actually the twist has to match the bullet. The longer the bullet the faster the twist needs to be - a short bullet should work in a fast twist barrel.

A longer/heavier bullet (depending upon which formula you use) will require a faster twist. With .223 there are lots of scare stories about over stabilising the bullets, but how stable do you want them?
Spinning too fast could potentially disintegrate the bullet but I have never heard of any first hand stories of it happening with bullets fired at normal .223 speeds. I regularly shoot 52gn bullets from a 1:7" twist travelling at breakneck speeds and the foxes don't know any different.

The upshot is faster twist is better, unless you're wildcatting and pushing the envelope regarding pressures and velocities.
With the 1:8" twist rate you should be able to shoot the heavy 75/77gn bullets and possibly even the 80gns but you'll have to try it and see what your barrel limits are.
I think that is a generalisation. You don't buy the bullets and match the rifle. You use the bullets that are most suited to the gun. It likes saying get a shotgun with a 3 inch chamber and you can shoot anything through it from 2" to 3".
On that basis why not just buy a 1:6 twist and you can shoot anything through it.

My .223" was 1:8 I could get clover leaf groups at 100 yards, (prone unrested with a scope) with 68 gr Sierra Match Kings and 68gr Hornady.
I tried the military bullet and it was on target but would have need developing to be accurate, maybe! I have tried 55gr bullets and they were not suited at all to my rifle. Since the one I was using were good enough I stayed with them rather than go to the expense and time trying to develop a load. The 55gr might work in the faster twist but it might not. It didn't for me.

If you are going to shoot mostly 55gr bullets why buy a rifle with a fast twist?