What is it about these bullets that makes the BC so high as compared to other brands of the same weights?

For instance, the BC of the triple shock 165, 308 is .505

The nosler 165 BT has a BC of .475,

thoughts?

That's a good question and one that will get lots of replys and OPINIONS. Barnes bullets are made of pure copper and are longer than bullets that have lead in them so....often a barnes has a "supposed" bc of the next heavier lead bullet. Ie a 165 barnes "might" be the same bc as say a 180 of someone elses.

All that being said take the BC with a grain of salt. There are long range shooters that say the bc of Barnes is pretty much right on to about 500 yds and then it falls off after that.

Bottom line is that you should try them in your gun and see if they match the charts. I've come to believe that to get anywhere near the charts the load has got to be ACCURATE in the gun to be anywhere near the mfg's bc.

Barnes is full of beans. Those numbers are just made up to sell bullets. Ignore them and sight your gun in yourself. It's too bad.

A Barnes techie told me they haven't actually assigned BC's by testing.They used Barnes x numbers. As you probably know BC actually changes with velocity. They usually list best case numbers