We'll the 50 is far denser than the 6.5. You should have taped phonebooks tightly together for a more scientific study.. The 6.5 bullet is fragile compared to the .50 and is not meant to hit anything as tough as catalogs or phonebooks. I shot .270 win 130gr bronzetips behind a max load of 4350 into magazines taped together about 1.5ft thick. The performance was shocking, the bullet penetrated about halfway before disintegrating almost entirely except for the bronze tip which was slightly warped and the thin copper jacket base which rolled into a ball. I shot handcast 158 gr lead hollowpoints into the same bulletcatcher and they penetrated roughly 6" but didnt open up more than .40 a standard fmj 38 special load penetrated 3" and opened up to more than twice its original size. Sorry to ramble off topic im done now
