Can't believe there's no Specs set (or even a mention) for Magneton yet.
http://www.smogon.com/dp/pokemon/magneton
QC - 2/2, GP - 2/2
[SET]
name: Choice Specs
move 1: Thunderbolt
move 2: Flash Cannon
move 3: Hidden Power Water / Hidden Power Grass
move 4: Explosion / Signal Beam
item: Choice Specs
ability: Magnet Pull
nature: Rash / Modest
evs: 80 Atk / 252 SpA / 176 Spe
ivs: 30 SpA / 30 Spe
[Set comments]
<p>With the abundance of bulky Water-types and other Electric-weak Pokemon in the UU tier, Electric is one of the best STABs to have. Magneton boasts the highest Special Attack stat out of all the Electric-types available in UU, and this set takes full advantage of that by utilizing Choice Specs. With the boost from Choice Specs, Magneton reaches a monstrous 556 Special Attack (factoring in the imperfect IVs from Hidden Power), which allows it to leave gaping holes in the opponent's team. While Magneton's defenses are nothing to write home about and its Speed is subpar, it can still switch in multiple times during a match to dish out hefty blows by relying on its 13 resistances. Thunderbolt is Magneton's main STAB attack and will badly hurt any Pokemon that does not resist it. Flash Cannon is Magneton's secondary STAB move and hurts most Pokemon that resist or are immune to Thunderbolt. While Hidden Power Grass has better coverage alongside Magneton's STAB attacks, Hidden Power Water is preferred since it allows Magneton to take full advantage of its ability, Magnet Pull, by allowing it to severely dent Steelix. However, Hidden Power Grass is still a great option if one is not worried about trapping Steelix, as it OHKOes Quagsire and Gastrodon while 2HKOing Lanturn. Explosion rounds out the set by giving Magneton a means to OHKO Chansey after Stealth Rock damage. If one doesn't like blowing Magneton up, Signal Beam can be used over Explosion in order to hit Grass-types like Tangrowth and Leafeon for super effective damage. Here are some damage calculations to exhibit Magneton's power:</p>
<ul class=”damage_calculation”>
<li>Thunderbolt vs 252 HP / 252 SpD Careful Registeel: 35.71% - 42.31%</li>
<li>Thunderbolt vs 4 HP / 0 SpD Venusaur: 39.74% - 47.02%</li>
<li>Thunderbolt vs 252 HP / 252 SpD Calm Clefable: 47.21% - 55.58%</li>
<li>Thunderbolt vs 252 HP / 216 SpD Careful Altaria: 48.59% - 57.63%</li>
<li>Flash Cannon vs 4 HP / 0 SpD Venusaur: 67.55% - 79.47%</li>
<li>Flash Cannon vs 252 HP / 252 SpD Careful Torterra - 41.12% - 48.73%</li>
<li>Hidden Power Water vs 252 HP / 252 SpD Sassy Steelix: 63.28% - 74.58%</li>
<li>Hidden Power Grass vs 40 HP / 252 SpD Careful Lanturn: 50.87% - 59.85%</li>
<li>Explosion vs 4 HP / 252 Def Chansey: 93.46% - 100%</li>
</ul>
[Additional comments]
<p>The given EVs allow Magneton to outspeed, trap, and OHKO Jolly Aggron. Max Special Attack and a Rash nature allow Magneton to hit as hard as possible, and the remaining EVs go into Attack to power up Explosion. Should one pick Signal Beam instead of Explosion in the last slot, a Modest nature is preferred and the Attack EVs should be distributed into HP so Magneton's average bulk is not compromised. Thunder is another daring option over Explosion. While the 70% accuracy is a huge turnoff, its power allows Magneton to 2HKO Registeel with a layer of Spikes most of the time, while utterly maiming almost all switch-ins. If one is using Magneton on a Rain Dance team, Thunder becomes much more appealing, due to its perfect accuracy in rain, and could even be used over Thunderbolt.</p>
<p>It should be noted that while it may be extremely tempting to bring Magneton out and start spamming Thunderbolt from the get-go, one must avoid this temptation, because although Thunderbolt is a fantastic STAB move, it does have its disadvantages. Dangerous Ground-types such as Rhyperior, Torterra, and especially Dugtrio are all itching to switch into Thunderbolt, and can use the free turn Thunderbolt gives them to set up, or, in Dugtrio's case, completely remove Magneton from the field. Due to this, it is usually better for Magneton to start off by scouting with either Flash Cannon or Hidden Power to catch Ground-types or Electric-resistant Pokemon first, only using Thunderbolt later in the match after the opponent's team has been properly scouted.</p>
<p>Chansey can switch into any attack Magneton can dish out apart from Explosion and heal itself with Wish or Softboiled. Due to this, strong Fighting-type teammates such as Hitmonlee and Hariyama are recommended, since they can easily scare off Chansey. Dugtrio can also be employed to trap and take out Chansey without too much trouble. Specially Defensive Torterra, when at full health, is also a good check to Magneton, as it is immune to Thunderbolt, isn't 2HKOed by Flash Cannon, and can OHKO back with Earthquake. Swords Dance Leafeon is a good partner to Magneton due to this reason, as it is able to set up on Torterra and proceed to sweep. In exchange, Magneton can trap and severely weaken Registeel beyond repair for Leafeon. After two Thunderbolts, Registeel will be too weak to stand up to Swords Dance Leafeon's assaults. Nasty Plot Mismagius is another Pokemon that can take advantage of a weakened Registeel. Magneton can also weaken Steelix with Hidden Power Water, so Pokemon that can sweep when Steelix is weakened are also good partners for Magneton. With Steelix gone, Swords Dance Scyther, Swellow, Choice Band Kangaskhan and other physical Normal- and Flying-types can sweep teams with a lot less effort. Altaria is possibly Magneton's best teammate, synergizing extremely well with it; in fact, the pair resists every type in the game. With opposing Steel-types weakened or removed, Altaria can fearlessly devastate an opposing team with its Dragon Dance-boosted Outrages. Magneton also easily scares away Milotic (although do not switch into any of Milotic's STAB attacks, as they will greatly damage Magneton), which is helpful because Milotic can severely damage Altaria with Ice Beam or remove its boosts with Haze. Other UU Dragon-types such as Shelgon and Dragonair achieve similar results.</p>

http://www.smogon.com/dp/pokemon/magneton
QC - 2/2, GP - 2/2
[SET]
name: Choice Specs
move 1: Thunderbolt
move 2: Flash Cannon
move 3: Hidden Power Water / Hidden Power Grass
move 4: Explosion / Signal Beam
item: Choice Specs
ability: Magnet Pull
nature: Rash / Modest
evs: 80 Atk / 252 SpA / 176 Spe
ivs: 30 SpA / 30 Spe
[Set comments]
<p>With the abundance of bulky Water-types and other Electric-weak Pokemon in the UU tier, Electric is one of the best STABs to have. Magneton boasts the highest Special Attack stat out of all the Electric-types available in UU, and this set takes full advantage of that by utilizing Choice Specs. With the boost from Choice Specs, Magneton reaches a monstrous 556 Special Attack (factoring in the imperfect IVs from Hidden Power), which allows it to leave gaping holes in the opponent's team. While Magneton's defenses are nothing to write home about and its Speed is subpar, it can still switch in multiple times during a match to dish out hefty blows by relying on its 13 resistances. Thunderbolt is Magneton's main STAB attack and will badly hurt any Pokemon that does not resist it. Flash Cannon is Magneton's secondary STAB move and hurts most Pokemon that resist or are immune to Thunderbolt. While Hidden Power Grass has better coverage alongside Magneton's STAB attacks, Hidden Power Water is preferred since it allows Magneton to take full advantage of its ability, Magnet Pull, by allowing it to severely dent Steelix. However, Hidden Power Grass is still a great option if one is not worried about trapping Steelix, as it OHKOes Quagsire and Gastrodon while 2HKOing Lanturn. Explosion rounds out the set by giving Magneton a means to OHKO Chansey after Stealth Rock damage. If one doesn't like blowing Magneton up, Signal Beam can be used over Explosion in order to hit Grass-types like Tangrowth and Leafeon for super effective damage. Here are some damage calculations to exhibit Magneton's power:</p>
<ul class=”damage_calculation”>
<li>Thunderbolt vs 252 HP / 252 SpD Careful Registeel: 35.71% - 42.31%</li>
<li>Thunderbolt vs 4 HP / 0 SpD Venusaur: 39.74% - 47.02%</li>
<li>Thunderbolt vs 252 HP / 252 SpD Calm Clefable: 47.21% - 55.58%</li>
<li>Thunderbolt vs 252 HP / 216 SpD Careful Altaria: 48.59% - 57.63%</li>
<li>Flash Cannon vs 4 HP / 0 SpD Venusaur: 67.55% - 79.47%</li>
<li>Flash Cannon vs 252 HP / 252 SpD Careful Torterra - 41.12% - 48.73%</li>
<li>Hidden Power Water vs 252 HP / 252 SpD Sassy Steelix: 63.28% - 74.58%</li>
<li>Hidden Power Grass vs 40 HP / 252 SpD Careful Lanturn: 50.87% - 59.85%</li>
<li>Explosion vs 4 HP / 252 Def Chansey: 93.46% - 100%</li>
</ul>
[Additional comments]
<p>The given EVs allow Magneton to outspeed, trap, and OHKO Jolly Aggron. Max Special Attack and a Rash nature allow Magneton to hit as hard as possible, and the remaining EVs go into Attack to power up Explosion. Should one pick Signal Beam instead of Explosion in the last slot, a Modest nature is preferred and the Attack EVs should be distributed into HP so Magneton's average bulk is not compromised. Thunder is another daring option over Explosion. While the 70% accuracy is a huge turnoff, its power allows Magneton to 2HKO Registeel with a layer of Spikes most of the time, while utterly maiming almost all switch-ins. If one is using Magneton on a Rain Dance team, Thunder becomes much more appealing, due to its perfect accuracy in rain, and could even be used over Thunderbolt.</p>
<p>It should be noted that while it may be extremely tempting to bring Magneton out and start spamming Thunderbolt from the get-go, one must avoid this temptation, because although Thunderbolt is a fantastic STAB move, it does have its disadvantages. Dangerous Ground-types such as Rhyperior, Torterra, and especially Dugtrio are all itching to switch into Thunderbolt, and can use the free turn Thunderbolt gives them to set up, or, in Dugtrio's case, completely remove Magneton from the field. Due to this, it is usually better for Magneton to start off by scouting with either Flash Cannon or Hidden Power to catch Ground-types or Electric-resistant Pokemon first, only using Thunderbolt later in the match after the opponent's team has been properly scouted.</p>
<p>Chansey can switch into any attack Magneton can dish out apart from Explosion and heal itself with Wish or Softboiled. Due to this, strong Fighting-type teammates such as Hitmonlee and Hariyama are recommended, since they can easily scare off Chansey. Dugtrio can also be employed to trap and take out Chansey without too much trouble. Specially Defensive Torterra, when at full health, is also a good check to Magneton, as it is immune to Thunderbolt, isn't 2HKOed by Flash Cannon, and can OHKO back with Earthquake. Swords Dance Leafeon is a good partner to Magneton due to this reason, as it is able to set up on Torterra and proceed to sweep. In exchange, Magneton can trap and severely weaken Registeel beyond repair for Leafeon. After two Thunderbolts, Registeel will be too weak to stand up to Swords Dance Leafeon's assaults. Nasty Plot Mismagius is another Pokemon that can take advantage of a weakened Registeel. Magneton can also weaken Steelix with Hidden Power Water, so Pokemon that can sweep when Steelix is weakened are also good partners for Magneton. With Steelix gone, Swords Dance Scyther, Swellow, Choice Band Kangaskhan and other physical Normal- and Flying-types can sweep teams with a lot less effort. Altaria is possibly Magneton's best teammate, synergizing extremely well with it; in fact, the pair resists every type in the game. With opposing Steel-types weakened or removed, Altaria can fearlessly devastate an opposing team with its Dragon Dance-boosted Outrages. Magneton also easily scares away Milotic (although do not switch into any of Milotic's STAB attacks, as they will greatly damage Magneton), which is helpful because Milotic can severely damage Altaria with Ice Beam or remove its boosts with Haze. Other UU Dragon-types such as Shelgon and Dragonair achieve similar results.</p>