Just a thought of where to get some schematics in NV with reasons provided (and not just big guns).
Deathclaw Gauntlet - Sloan, i'd think for obvious reasons. If you're gutsy enough to go try to slay a deathclaw at that early of a level you deserve to make it. Get it from that lady at the bar who also makes the omelettes. Or better yet have her give you the recipe for both the omelette and the gauntlet when you bring her a deathclaw egg.
Rock-It Launcher - sold by Chet, so its early game accessible as per F3 with Moira.
Railway Rifle - sold at Mick and Ralph's, a polite society is an armed society.
Bottlecap Mine - sold by Cliff Briscoe in Novac, or can be looted from the irradiated locked room behind his desk.
Shishkebab - perhaps a reward for beating all of the combatants in the Legion Arena, gives some incentive to do that series of micro-quests.
Nuka Grenade - given by Fantasitc at Helios One after completing his relevant quest, or you can kill him and it's on his corpse.
Dart Gun - not sure about this one, maybe hidden inside a toy crate at the children's barracks at Nellis?
Side note, I like all the ideas posted here. Big Guns would be a great addition to regular gameplay and would do good to shake up my common builds and make me try new things. Y'all keep doing God's work.
