My first problem with this is the twist rate, really 1-7! A 1-7 will not stabilize 55 grain rounds worth a chit, that twist is for 60+ grain rounds. I can run 62 grain rounds through my 1-9 with no problem or loss in accuracy. This move towards slow heavy rounds defeats the purpose of what is considered hi velocity rounds. I’m on a ranch every day and carry several rifles, none of my rifle ammo combinations shoot less than 3500 fps. On one rifle I run a 1-12, it’s STEYR pro hunter 243 running around 3950 with a 58 grain pill.
“On one rifle I run a 1-12, it’s STEYR pro hunter 243 running around 3950 with a 58 grain pill.”
Dude! Instant mail.
You are correct, sir. Avid .223/5.56 reloader here. None of my 1-7 twist 55 grain well at all. In my opinion, the author is very mistaken about 16” being all you need in a battle rifle. If you’re running FMJs there is a huge advantage to running a 20” barrel (I’ll even concede an 18”) to keep your velocities in fragmentation range.
The military running m855 in 14.5” barrels for as long as they did was total lunacy.
Nonsense. Try this this link for advice from a ballistician:
Understanding Twist: Bullet Stabilization
The reason the military settled on a 1:7 twist is to stabilize the M856 tracer. It's about the same length as a 80 grain BTHP.