I think the bone is still most beneficial(then again I haven’t gotten the Hard Carry) But personally I didn’t like that weapon at all for Zer0 on the peak but I’d say play around with it and see what you like.
Edit: Also, I did have the easy mode shield with it but I felt like more I got more dmg out the bee.
I did a few rounds on 80 Pete with Axton using a Bee and Peak Opener. based on experience, Explosive relic deals more damage per shot. However the cooldown rate on the Bone makes it better in the long run.