help with 6.9spc

[halfbakedi420]

was looking to make a 6.8 spc for an ar. i was looking at 20-24 inch bull bore.
I was wanting opinions on length, twist and lands. i know i want the target crown not the threads.
what say you?

 

[sinarms]

it's a good round, I have made quite a few barrels in it. I use a 6.8 SPC II spec reamer as do all of the other guys that know what is going on with the round. You still see some of the standard SPC chambers out there but most are the II