Personally, I don't think you need one for 7-08. I do have one posi-lock scope on my 7.82 Patriot, but I never use the Posi-lock feature. I am push a 150 grain @ 3001 FPS and a 180 grain bullet @ 2725 FPS and it hasn't been a problem for me yet. Scope is the 3-12 Burris LER.
Ernie