are there any lightweight semi-automatic rifles good for hunting?

[Marshish]

Definitely Benelli R1!!! I have one in 300 wim mag and it's very lite. Due to the gas system and the comfort tec stock, the recoil is very manageable (comparable to a .308) . I am running 180 grain browning ammo and getting very respectable groups. (Around 1moa)

 

[captonion]

The BAR is great but is huge like it's military namesake.

Not even! The new models are lighter and more ergonomic..

 

[RangerPark]

Benelli R1 in .300 or .338 Win Mag, or equivalent BAR. Most other NR semi-auto out there don't have enough firepower to justify their weight in a hunting scenario. Sure hunting with a lightweight Stag-10 in 6.5 CM or .308 would be fun, but for the same weight the R1 packs a much bigger punch.