I originally built this team around Mamoswine, because I feel it's a threat that many teams are not prepared for. However, it's undergone so many changes that it doesn't really revolve around him anymore. But here it is. I'm very open to any suggestions/criticism.
Heatran@Choice Scarf
Modest 20 HP/252 SpA/236 Spe
-Fire Blast
-Earth Power
-Hidden Power Ice
-Explosion
I've had moderate success with Heatran as a lead. Bronzong almost never stay in because of Fire Blast. Gengar is always OHKO'd by Fire Blast, which is nice if they don't expect me to be scarfed. Heatran is important to kill Bronzong and Skarmory, which can stop a Mamo or Chomp sweep. It can also switch in on Azelf. Midgame, I sometimes explode on Blissey or Cresselia when I feel he has served his purpose, although sometimes I keep him to revenge kill Garchomp with HP Ice. ScarfTran is an important part of the team.
Swampert@Leftovers
Relaxed 240 HP/216 Def/52 SpA
-Stealth Rock
-Earthquake
-Surf
-Ice Beam
MixPert. Stealth Rock is important to get the residual damage I need for some important KOs, like Fire Blast on Sassy Bronzong. I am considering Stone Edge on Swampert because of my Gyarados problems. Good switch in to the Fire types that threaten Mamo like Heatran and Arcanine. Infernape kills it with Grass Knot, but if it has Grass Knot then it doesn't have Thunderpunch, and Gyarados can kill it. Haven't had to use it yet, but I assume it could take on Weavile.
Snorlax@Choice Band - Thick Fat
Adamant 252 Atk/252 SpD/4 HP
-Body Slam
-Earthquake
-Fire Punch
-Selfdestruct
A new member of the team that has been working surprisingly well at blocking special hits. An excellent counter to Gengar, though he lacks Pursuit (illegal with Selfdestruct and Fire Punch, and I think those two are more valuable). Snorlax can switch in on most special attackers (Focus Blast from Alakazam does 47-56%) and hit back hard with STAB Body Slam. When its HP is low enough that it will probably only get one more switch in, he Selfdestructs (incredibly powerful with CB + STAB). Many targets who can't KO him are forced to switch or die, giving him a nice hit on whatever comes in.
Gyarados@Life Orb
Adamant 252 Atk/252 Spe/4 HP
-Waterfall
-Stone Edge
-Earthquake
-Dragon Dance
I originally ran a Lucario in this spot, but I feel this helps the Gyara and Infernape weakness that I previously had, but is still capable of doing some damage. After a DD, he does 69-81% to Max Def/HP Bold Blissey (though many don't run that anymore), and in the late-game has swept many a team. One of the reasons I added him was to somewhat take care of other Gyarados - Intimidate on the switch-in and Stone Edge, since many Gyara don't have SE and even if they do they're intimidated. I've been considering a bulkier version, but I think I'll miss the power/speed of this one. Opinions?
Garchomp@Yache Berry
Jolly 252 Atk/252 Spe/4 HP
-Swords Dance
-Earthquake
-Fire Fang
-Outrage
I'm sure you know that Garchomp is one of the most dangerous threats in the game. Jolly/Yache seems to be the most effective Chomp I've tested, and after a SD it almost always takes out at least one Poke - especially since Heatran takes care of two of its main counters, Bronzong and Skarmory. He is a great mid-to-late game sweeper, though I'm certainly open to changing him. Another thing I considered is Stone Edge over Fire Fang (I know, I'm paranoid about Gyara >_>).
Mamoswine@Life Orb
Naughty 252 Atk/64 SpA/192 Spe
-Ice Shard
-Blizzard
-Earthquake
-Stone Edge
Mamoswine is a versatile attacker that can sweep teams that aren't prepared. Ice Shard will either de-yache or KO Chomp (though he's hopefully already dead by the time Mamo comes out). Not many things can take STAB 130 Attack LO Earthquakes, especially late game when their counters are weakened. I didn't band it because it seems it's wasting a lot of its potential as a cleaner.
Thanks for reading, I'm very open to any suggestions that can help me improve the team.

Heatran@Choice Scarf
Modest 20 HP/252 SpA/236 Spe
-Fire Blast
-Earth Power
-Hidden Power Ice
-Explosion
I've had moderate success with Heatran as a lead. Bronzong almost never stay in because of Fire Blast. Gengar is always OHKO'd by Fire Blast, which is nice if they don't expect me to be scarfed. Heatran is important to kill Bronzong and Skarmory, which can stop a Mamo or Chomp sweep. It can also switch in on Azelf. Midgame, I sometimes explode on Blissey or Cresselia when I feel he has served his purpose, although sometimes I keep him to revenge kill Garchomp with HP Ice. ScarfTran is an important part of the team.

Swampert@Leftovers
Relaxed 240 HP/216 Def/52 SpA
-Stealth Rock
-Earthquake
-Surf
-Ice Beam
MixPert. Stealth Rock is important to get the residual damage I need for some important KOs, like Fire Blast on Sassy Bronzong. I am considering Stone Edge on Swampert because of my Gyarados problems. Good switch in to the Fire types that threaten Mamo like Heatran and Arcanine. Infernape kills it with Grass Knot, but if it has Grass Knot then it doesn't have Thunderpunch, and Gyarados can kill it. Haven't had to use it yet, but I assume it could take on Weavile.

Snorlax@Choice Band - Thick Fat
Adamant 252 Atk/252 SpD/4 HP
-Body Slam
-Earthquake
-Fire Punch
-Selfdestruct
A new member of the team that has been working surprisingly well at blocking special hits. An excellent counter to Gengar, though he lacks Pursuit (illegal with Selfdestruct and Fire Punch, and I think those two are more valuable). Snorlax can switch in on most special attackers (Focus Blast from Alakazam does 47-56%) and hit back hard with STAB Body Slam. When its HP is low enough that it will probably only get one more switch in, he Selfdestructs (incredibly powerful with CB + STAB). Many targets who can't KO him are forced to switch or die, giving him a nice hit on whatever comes in.

Gyarados@Life Orb
Adamant 252 Atk/252 Spe/4 HP
-Waterfall
-Stone Edge
-Earthquake
-Dragon Dance
I originally ran a Lucario in this spot, but I feel this helps the Gyara and Infernape weakness that I previously had, but is still capable of doing some damage. After a DD, he does 69-81% to Max Def/HP Bold Blissey (though many don't run that anymore), and in the late-game has swept many a team. One of the reasons I added him was to somewhat take care of other Gyarados - Intimidate on the switch-in and Stone Edge, since many Gyara don't have SE and even if they do they're intimidated. I've been considering a bulkier version, but I think I'll miss the power/speed of this one. Opinions?

Garchomp@Yache Berry
Jolly 252 Atk/252 Spe/4 HP
-Swords Dance
-Earthquake
-Fire Fang
-Outrage
I'm sure you know that Garchomp is one of the most dangerous threats in the game. Jolly/Yache seems to be the most effective Chomp I've tested, and after a SD it almost always takes out at least one Poke - especially since Heatran takes care of two of its main counters, Bronzong and Skarmory. He is a great mid-to-late game sweeper, though I'm certainly open to changing him. Another thing I considered is Stone Edge over Fire Fang (I know, I'm paranoid about Gyara >_>).

Mamoswine@Life Orb
Naughty 252 Atk/64 SpA/192 Spe
-Ice Shard
-Blizzard
-Earthquake
-Stone Edge
Mamoswine is a versatile attacker that can sweep teams that aren't prepared. Ice Shard will either de-yache or KO Chomp (though he's hopefully already dead by the time Mamo comes out). Not many things can take STAB 130 Attack LO Earthquakes, especially late game when their counters are weakened. I didn't band it because it seems it's wasting a lot of its potential as a cleaner.
Thanks for reading, I'm very open to any suggestions that can help me improve the team.