Borderlands uses a classification system for gear that follows a color-coding system for RPGs (which was pioneered by Blizzard’s).
You should ALWAYS add Moonstones to the grind, because this gives you the best chance at getting a higher rarity/legendary item AND if you do get a legendary item, it can bestow a Luneshine enchancement which are as follows:
Fast Learner: Bonus to XP from kills
Harden Up: Improves Maximum Shield Capacity
Boominator: Increases grenade damage
Safeguard: Restores some of your shields with each kill
Oxygenator: Damaging enemies restores O2
Piercing Rounds: Grants a change to ignore enemy shields
Punisher: Raises critical hit damage
Serenity: Reduces rate of O2 consumption
The level of your weapons MATTER. It appears there is an average applied to the produced weapon based upon the levels you put in (e.g. 38+39+40=39).
Putting in 3 weapons of the same manufacturer (i.e. Hyperion) will not give you the same manufacturer back.
You will not be able to grind most unique weapons (those with red letters and usually in blue/purple/orange rarities).
Components: 2 legendaries and one purple item
– The PURPLE item indicates the legendary base type
– Lowest level item used determines the level
– ADD MOONSTONES! Otherwise you WILL NOT have a chance to get the Luneshine enchancement.
Components: 3 items of the same type and rarity
– Works from Green to Purple, but not Legendary.
– If you DON’T use moonstones, you might get the same rarity back, so beware!
Go up one rarity
Components: 3 different type items of same rarity
– Also seems to work for 2 of one type and one of another
Components: 3 blue unique items
– As noted above, you WILL NOT get any special grind effects from doing 3 blue unique items, it only will guarantee a PURPLE in return.
Rocket Launcher: Components: 2 weapons and 1 grenade mod (same rarity)
Components: Shield + SMG + Sniper Rifle
Components: Shotgun + Sniper Rifle + Shield
Components: SMG + Pistol + Shield
Components: Assault Rifle + Pistol + Shield
Class Mod of Next Rarity:
Components: Any 3 class mods of same rarity
– Gives back class mod of the character who uses the grinder