Had a similar issue with my 6.5 CM this season. Hornady Precision Hunter (143ELDX) left no exit wound or blood trail, but tore up the vitals. 143ELDX handloads left a good exit wound. I switched to Nosler Ballistic Tip factory ammo and do get an exit wound.
Yup,. I only Shoot, HANDLOADS with Chron'od KNOWN Velocities at, Big Game as,..
Who know's just "What," the Factories are, "really" putting Out ? My 143 -X's are going 2,725 FPS,..+- a Tiny Bit, EVERY Time !
Berger's 140 gr., "Hunting Version" Bullets and 143 gr. ELD-X's have Performed, very Well for, Our Family in, the .270 WSM and 6.5's.
I have only Used, Handloads since, 1964 ( Gov'mnt 4895 with, Hornady 180's / 150's Later, in my $17.50 1903 A3, "Sporterized" Springfield just,.. "Worked" ).
OOP's,.. I did Shoot, a Fat ole' Doe once, with Factory 55 gr. SP's from my .22-250 Rem. 700,.. NOT, a "Good idea" as, LOTS of, Tracking was, involved !!