Weak toRockSteelWater ×1.6

Attacker	Type	Moveset	DPS
Metagross	SteelPsychic	Bullet PunchMeteor MashLegacy	13.1
Inteleon	Water	Water GunHydro CannonLegacy	12.9
Kyogre	Water	WaterfallOrigin PulseLegacy	12.9
Tinkaton	FairySteel	Fairy WindGigaton HammerLegacy	12.8
Glimmora	RockPoison	Rock ThrowMeteor Beam	12.7
Rampardos	Rock	Smack DownRock Slide	12.6
Lucario	FightingSteel	Force PalmMeteor MashLegacy	12.5
Kingler	Water	BubbleCrabhammer	12.2
Greninja	WaterDark	Water ShurikenHydro CannonLegacy	12.2
Eternatus	PoisonDragon	Dragon TailDynamax CannonLegacy	11.9
Tyrantrum	RockDragon	Rock ThrowMeteor Beam	11.8
Gigalith	Rock	Lock OnMeteor BeamLegacy	11.8

Rainy boosts the Water attacks above. Partly cloudy and Rainy boost Shuckle.

Level 40, 15 attack IV, costed against Shuckle's own defense and typing, one per evolution family.

Shuckle's moveset, CP and shiny All counters Raid board

Questions people ask

What is Shuckle weak to in Pokémon GO?

Shuckle takes 1.6 times from Rock, Steel and Water.

What's the best counter to Shuckle?

Metagross with Bullet Punch and Meteor Mash, worth 13.1 damage per second against Shuckle's own defense. The full ranking is above.