Do you have a link? AR platform barrels tend to be made in 1:9-1:7 twist.... Most 22 LR are built around 1:16 twist.
do you know the twist rate on the 18: barrel you are looking to use?
Unless you want to shoot specialty ammo- say the SSS ammo... you don;t need any more twist than 1:16
I picked up a used USGI upper to use as a 22LR upper with a 1:14" twist... it's fairly accurate, but not match