Oh great metagross -_-

EV's 252 atk, 252 speed, 4 HP / Sp.def
Clear Body
Ice punch
Meteor Mash / Bullet Punch
Bullet Punch / Hammer Arm / Thunder Punch

I don't really recommend thunder punch or using the ability heavy metal, as it will ensure almost 1KO death from nearly any low kick I do recommend bullet punch because its metagross' only priority move except pursuit, I don't recommend this set unless you want to risk lower power, and slowness, next set please

Gravygross / Metaclaws
EV's 252 Attack, 252 Speed, 4 HP
Clear Body
Meteor Mash
Ice Punch
Gravity / Hone Claws
Hammer Arm / Rock Slide

Gravity decreases everything evasion meaning including yours so almost everything is guaranteed to hit, or go with the set up of Hone Claws to increase your accuracy for your attacks that need it, and decent attack, Ice Punch coverage, Meteor Mash Stab, and hammer arm or rock slide for coverage and hammer arm works great in a trick room

EV's 252 HP, 252 Sp.def, 4 Defense
Clear Body
choice Band
Meteor Mash
Ice Punch / Hammer Arm
Earthquake / Rock Slide

Attacks for coverage, and hammer arm for speed drop in trick room, which really helps