Curiosity got me thinking of: at what point is the article referring to in respect to "Because energy was roughly the same.."
So, I looked up the specs of a .303 and the 577/450 Martini and it appears the energy is roughly the from about 200 yds.
Too bad we don't know what they mean about the "wounds" as they stated the .303 was a HP and the .450 a solid.