Try shooting a cast bullet out of a two groove 303 British if you want an oblong bullet. Depending on the rifles bore you start out with say a .316 dia. bullet to fill the two small grooves and 3/4 of the bullet gets swaged down to fit the two larger .310 lands. Talk about a flat bullet,what amazing is that it still shoots very accurately.
I've Beagled a couple different mold in the past and it's worked fine.