Anybody know whether or not it is preferable to use a 1 in 14 inch twist barrel for 600gr Woodleighs out of the 505 Gibbs or is a 1 in 16 twist sufficient?

If you know what the Original Gibbs rifle twist was, then whatever they used in that is fine for
the 600gn Woodleigh's as we used my 505 Gibbs for testing the 600gns and they worked fine out of it. They kill well !!!


If needed - and let me know - I'll get mine out and put a cleaning rod through
it to see what the twist is.

.

The 600grain bullet was THE original bullet weight for the mighty .505 Gibbs.

George Gibbs changed the weight after 2-3 rifles made to 525 grain bullets -of what reason is still unknown.

Thanks for sharing your experiences. I'll probably go with the 1 in 16 twist.

anything faster than 1:20 will be fine ...

The CIP standard twist for the .505 Gibbs is 1:406.00mm, or 1:15.98".
I believe that to be the tradition from olden times.
That is the same twist A-Square used to generate their load manual data in a 26" barrel length, for the .505 Gibbs.

CZ used a 1:10" twist barrel from McGowen for their factory .505 Gibbs.
I can vouch for that fast twist being good with .505/525-grainers.
It would do even better as the bullet got heavier and longer.

16" twist ought to be the slowest twist considered, or anything faster twist than that, 14", 12", 10",
whatever twists your crank.