Twist rate to barrel length ratio

Rutland lad

Well-Known Member
Gentllemen - I seem to recall reading somewhere that most rounds should have a least two rotations in the barrel before exiting.
Is this a general rule of thumb ? Or did I read it in relation to my own Barnes TSX (180grain) in .30 cal ?
I know this would mean a barrel with a 1/12 twist rate would have to be 24" long, and many people shoot shorter barrelled weapons, as I do with my current 1/10 twist rate Steyr, which is just under 20" and is accurate enough for me.
I'm sure that I've seen this written down, as it apparently aids the round to stabilise. Or is that ratio the optimum ?

Am I dreaming this, or have I confused it with something else ?

Your thoughts would be appreciated.
 
There are a few articles where people have reduced the barrel length down to 16" (google it) with only limited loss of fps from the starting length.

I had the barrel reduced on my .223, but the mod put the length back on and balanced the rifle, the only loss being an impact on accuracy at distances over 500 yards, which I rarely use it for anyway.
 
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