5.56 twist rate ?

[Ax238]

I'm building an AR15 for calling coyotes for this Fall and I want to shoot 50-60gr bullets, but mostly 55 grainers. A 1/12 twist rate would be ideal but unless I order a custom barrel I'm looking at a 1/9 rate with a barrel ready to install in an upper. Is 1/9 too fast or is 1/12 too slow, there seems to be a lot of difference in opinion, but what are the facts ? Thanks

 

[lefty o]

1-9" is perfect for what you want.

 

[Larry Elliott]

A 1 in 12" twist might work with 60's, but a 1 in 9" twist will for sure work with 60's, and give good accuracy with lighter bullets too. I have a 1 in 8" twist AR that loves 60 gr Sierra HP's.

 

[243winxb]

AR15 barrel twists/load data

http://www.6mmbr.com/223Rem.html On the link page, click the green Sierra icon for load data.