Here is a great physical Mamoswine set.
Mamoswine @ Life Orb/Choice Band
Trait: Thick Fat
EVs: 4 HP/ 252 Atk/ 252 Spe
The point os this set? Simple. Earthquake and Icicle Crash are his two most powerful STAB moves. The two of them combined can hit everthing in its Tier either super or normal effectively! Plus, with his massive 130 base attack, he wil put massive dents in any Pokemon that decides to stay in and try to counter. Stone Edge adds coverage and allows him to hit even more Pokemon super effectively. Last, Ice Shard allows him to revenge kill a lot of Pokemon and not just breloom, Dragonite, Latios, and Salamence. With the added power from Life Orb or Choice band, he can usually at least 2HKO almost any Pokemon in the OU tier!!