276 Atk vs 368 Def & 420 HP (100 Base Power): 82 - 97 (19.52% - 23.10%)
Standard Rev, no boosts, Hammer Arm vs 252 HP 252 Def +Nature CAP8.
276 Atk vs 272 Def & 420 HP (100 Base Power): 109 - 130 (25.95% - 30.95%)
Standard Rev, no boosts, Hammer Arm vs 252 HP CAP8.
355 Atk vs 297 Def & 384 HP (95 Base Power): 123 - 145 (32.03% - 37.76%)
Max Spa +Nature CAP8 Thunderbolt vs Standard Rev.
355 Atk vs 297 Def & 384 HP (95 Base Power): 160 - 189 (41.67% - 49.22%)
Same calc with Life Orb.
I can 3hko you. Meaning that even if you rest, I hit you once, twice, then KO you faster than you can rest up again. Even with Shed Skin, consider that you have to worry about crits and running out of PP. LO/Specs means I beat you straight up. I'd call it a check at most, and if it gets CM take it off the list completely.