Weezing can take two +2 Rock Slides / Returns? Whaaat?
These are all for 252/252+ Weezing
Jolly +2 Rock Slide: 107-126
Jolly +2 Return: 145-171
Jolly +2 LO Rock Slide: 136-161
Jolly +2 LO Return: 186-219
Adamant +2 Rock Slide: 118-139
Adamant +2 Return: 159-188
Adamant +2 LO Rock Slide: 151-178
Adamant +2 LO Return: 204-241
It can take them (especially Rock Slide) if Excadrill doesn't have Life Orb. +2 LO Return is pretty much a losing game for Weezing, though.
If it takes minimum damage from the strongest Return, it's left with 130 HP. Assuming it hits with Will-o-Wisp, Excadrill's damage the next turn is reduced to 123 Maximum, and it can use Pain Split next.
It's not the best check, but you'd be surprised how well Weezing can work to halt physical attackers. I really don't know why more people didn't use LO Excadrill, since it's by far the most dangerous variant.
One more note about Excadrill: it can't always have all of Swords Dance, Return, X-Scissor, Rapid Spin, Substitute (possibly), and other moves, which helps in countering it. (Tangrowth does well if it doesn't have X-Scissor, taking 237 maximum from Adamant +2 LO Return, which allows it to Earthquake/Leaf Storm as a follow-up)