It also talks to the instability that was designed into the 5.56 cartridge and the Stoner rifle. They called for a 1 in 14 twist that would produce a pretty unstable bullet.
Not exactly correct.
The author is comparing apples to God knows what and should have applied more research and common sense into his article.
1 in 14" is OK for stabilizing a 55gr bullet, *until* you get to below freezing temps as noted.
Current Remington .223 varmint rifles have 1 in 12 and do just fine with bullets up to 64gr.
The tip of the bullet would move in a tiny circle around the axis of travel guaranteeing it would tumble upon impact.
{{{
cough cough bullshit!! cough }}}
Doesn't guarantee anything since
ALL bullets do this...from 22lr to 16" Iowa class guns.
In order for there to be zero yaw, the bullet, barrel, chamber, i.e.
everything would have to be made absolutely PERFECT with NO +/- variation at all....and that hasn't happened yet.
Impact velocity has more to do with the tumbling and/or fragmentation of a fmj bullet than rifling twist ever did.
Anyway, this design instability is also covered in the article and the reasons the twist went from a devastating 1 in 14 to a very stable 1 in 7 twist.
They went to a faster twist to get stability for the longer 62gr SS109/855 bullets. (and the longer yet
tracer bullets)
Not only are they heavier, they are long for their weight due to not being
all lead.
(same reason Barnes bullets are long for their weight - no lead)