For WT in that cartridge I don't think you could go wrong with a ballistic tip, AccuBond, sst, or Berger. I bet they'd all result in bang flops. If it were me, I'd use whichever one of those four shoot the best.
I've taken deer with the 140 hot- cor, 140 gameking, and 129 interlock with my Creedmoor. I'm the .260 I used a lot of 120 ballistic tips and 130 accubonds. All of them have performed excellent for me.
What is the typical distance of your shots? Are you a shoulder puncher, high shoulder, behind the shoulder lung shot? Bullet choice depends a lot on the hunter and what type of shots they plan on/are willing to take and at what distance. If you are the typical hunter that plans on engagement distance of 10-200 yards and take generally broadside shots at or near the shoulder then I'd recommend the 130 AccuBond or 140 Partition. If you are a precision shooter and hunt at extended ranges then I'd go for the 129 ABLR or the 140 Berger in either the hunting VLD or the hybrid target. And yes I know the target line isn't intended for hunting but trust me...it gets the job done just fine!
As always find a bullet/load combo that your gun likes and become highly proficient in placing it where you want in field conditions. Bullet placement is king.....
I have shot a bunch of deer with 6.5x55 with 140 gr Sierra Game kings, 120 Pro hunters, Hornady 140 Interlock, 120 Nosler BT. Most were shoulder shot from spitting distance out to 350 yards mostly with some a little further away. Most were bang flop and all were dead within 50 yards. I shoot the 130 Nosler AccuBond in my 264 Win mag at 3350 fps and it is AWESOME out to a little over 500 yards so far. With most any HUNTING bullet it is hard to go wrong with a 6.5 on WT deer if you put it where it is supposed to go. It may not be the latest greatest new wizbang bullet to come down the road but for the money and accuracy and results on deer the 140 Sierra Game King is hard to beat.
I agree with 1Shot Ive been pretty partial to the gamekings for the last two years. Any 120-140 6.5mm hunting bullet is mighty deadly. I really like the cup n core bullets out of Creedmoor speeds I get in a 22" tube.