Semi autos usually have poor accuracy compared to bolt action rifles.
Some ARs are 2-3 MOA where most bolt actions are usually 1MOA or slightly better

GA Precision make custom bolt actions that are used in target shooting competitions.
One of the better custom options for building your own rifle.

They make a semi auto in .308 and other calibres like 6mm manbun you could get .260 rem or 7mm-08 as well.

This GAP 10 in .308 shoots less than 0.5 MOA which makes it a laser compared to most rifles.
They use quality parts like Bartlein barrels.

You would need Category D license for this one in Australia