RE: Can I load 30-30 bullets loaded in a .308
Absolutely. No need to reduce your loads either. I hunt with an XP100 in 308 Win and use bullets designed for 30-30 most of the time.
My favorite is Barnes 150 Gr TSX FN. I push it at 2650 fps and it works great. I also have used Sierra & Hornady 150 & 170 gr30's designed for the 30-30.
I've recovered a few of these bullets. They all expanded well and retained about as much weight as ones I've recovered from rifle shots. Before I loaded the Barnes bullet, I emailed Barnes and asked about pushing that bullet 400 fps faster than the 30-30. They said no problem.
As for "thick stuff", shape doesn't mean squat. A tiny twig can deflect a round nose just as well as a spitzter.