The two cartridges do almost the same thing except you can load the 308 with heavy for caliber bullets like the 220 grain Hornady or Nosler.
The 270, not so much.
Also, you can’t accidentally chamber a 270 in a 308 chamber and blow your gun up like a dumb ass.
The ranges are littered with the pieces of 270s that some knucklehead accidentally shot a 308 in.
