Every Capsule has different drop rates:
Common Weapon Capsule
[Total Cards: 49-51]
Normal: 36; Rare: 40%➞12, 60%➞13; Epic: 20%➞1, 80%➞2; Legendary: 0%
Rare Weapon Capsule
[Total Cards: 147-148]
Normal: 89; Rare: 49; Epic: 20%➞9, 80%➞10; Legendary: 0%
Epic Weapon Capsule
[Total Cards: 420]
Normal: 294; Rare: 105; Epic: 21; Legendary: 0%
MIB: International Pack
[Total Cards: 659-661]
Normal: 363; Rare: 198; Epic: 50%➞82, 50%➞83; Legendary: 50%➞16, 50%➞17