You can only assume the shots. Are well placed if the animals were not recovered.
Lots of fellas up here using cheap Federal ammo every year and dropping a ton of animals.
I have shot , developed loads , or personally hunted with over 10 different 6.5 cartridges from the 6.5 Mannlicher Schoenauer to the 6.5STW, and never had a problem with accuracy or killing power in any of them.
In the obsolete and " anemic " 6.5MS , we have used everything from cheap 160 grain round nosed bullets all the way down to 129 grain monos for everything from moose to coyotes.
They all work if you put them where they are supposed to go!

Cat