I put it on a 17HMR....for about ten minutes. To me it was a wobbly, light weight piece of junk. I sold it. If you want your rifle to feel like a kid's toy, go for it. I've also heard since of recoil collapsing the stock and causing scope eye or worse.
If you have the heavy barreled .308, it's gonna be way out of balance.
If you got the impression I didn't like it....you're correct.