Cheat sheet

Guns to Save -

Nameless Midnight (Vanguard Reward)
Better Devils (crucible Drop)
Antiope D (Gunsmith Drop)

Uriels Gift (Gunsmith Drop)
Tone Patrol (Gunsmith Drop)
Minuet-42 (Gunsmith Drop)
Anual Skate (Gunsmith Drop)
Manannan SR4 (Gunsmith Drop)
Last Hope (Gunsmith Drop)

Main Ingredient (Vanguard Drop)
Hawthornes Field Forged Shotgun (Gunsmith Drop, Planetary Drop Drop)
Curtain Call (Vanguard Drop)
Widow`s bite (Engram Drop, Planetary Drop, Gunsmith Drop)
Man O War (Reward IO)

Levling progression -

Finish Main story campaign. Save all quests. Buy Fireteam tokens from eververse with Bright dust. Do public events til 265 (save mile stones). Then do all mile stones, then exotic quests. Dont finish the STURM quest, having it active, will yield higher exotic drop rates.