Any weapon carries with it a bonus to attack based upon the type of weapon. Melee and Natural Weapons grant a bonus to Strength attacks while Ranged weapons grant a bonus to Agility attacks.

Bonuses range +1 to +10. 95% of weapons never grant higher than a +4 bonus. To have higher than a +4 bonus, there must be something exceptional about the weapon in either construction or origin and not just in power capabilities. There are maybe a handful of weapons which grant a bonus of +7 or higher.

Body Armor is the same in granting a bonus. Although bonuses for armor can reach higher on average, they tend to top out at +5, rarely reaching higher than that.

Some examples of both are listed below including examples for comparison to some Marvel superheroes' equipment.

Natural Weapons

Sabretooth's Claws +2
Sabretooth's Teeth +2
Rhino's Horn +5
Wolverine's Claws +2 (Bone)/+5 (Adamantium)

Melee Weapons

Small Knives +1
Billy Club +2
Large Knives +2
Quarterstaff +3
Most Swords +3
Katana +4
Absorbing Man's Wrecking Ball +5
Captain America's Shield +5
Thor's Mjolnir: War Hammer +7

Ranged Weapons

Small Caliber Pistol +2
Large Caliber Pistol +4
Green Goblin's Grenades +4
Small Caliber Rifles +3
Large Caliber Rifles +4
Heavy/Sniper Machinguns/Rifles +5

Body Armor

Kevlar Armor +2
Rhino's Armor +5
Juggernaut's Armor +7

IMPORTANT NOTE: Some weapons may have additional functions or powers within them.