assembly grease of somekind (should i remove from ar bolt assembly)

[stangman86gt]

So, i was taking apart my newly acquired RRA predator pursuit upper to give it the initial cleaning(yes, i'm one of the clean/lube my guns before i shoot them for the first time crowd) and I noticed on the back of the bolt assembly there is a massive amount of what i would assume to be moly grease.

Seeing as this is my first AR, i was wondering if this grease is necessary(can i take it off and use regular oil)? Everywhere I've read they only say oil not grease.

Let me know what your expertise says.

thanks,
mike

[luckystrike]

just clean everything up including the barrel, then re oil. they put grease on them because oil will dry up too quickly during storage.

[stangman86gt]

ok thats what i figured.

thanks again,
mike