The crafting system in New Vegas has always struck me as quite powerful, but I also feel that the developers didn't really iterate well on a lot of the default recipes in the game. I built this mod with the intention of "filling in" the crafting system - that is to say, I tried to reasonably iterate on the recipes already present in the game. There are quite a lot of new recipes in this mod - there are at least as many new ones as default new vegas recipes.

Some examples of additions include:
-More recipes based on using Fission batteries to charge energy cells
-Recipes for conversions of bulk or surplus ammo to standard ammo
-Recipes for making bullet primers
-Many more chem recipes
-Breakdowns for a lot of the useless trash you find in the wasteland (eg. hot plates, toasters, etc) - makes it significantly easier to build up a supply of scrap and/or lead
-The ability to make .22LR and BB rounds (for those of you who've ever wanted to use the Abilene Kid gun through the whole game)
-Lots of explosives recipes
-And more...

Download it, give it a try! Feel free to post feedback here.

Compatibility
This mod should be fairly widely compatible with other mods because it does not make any significant changes to the base game content, it only adds new recipes.
This mod is also fully compatible and balanced with A Tale of Two Wastelands. Although it only relies on Fallout: New Vegas, many of the recipes added by New Vegas Extended Crafting are quite useful in the D.C. wasteland.

--Update 1.1
Added "Soylent" cooking recipes unlocked when you gain the Dine and Dash! perk
Added the ability to convert bullet cases between similar types (similar, in this case, means "uses the same primer type")

--Update 1.2
Added Stealth Boy recipe
Changed Overcharged energy recipes to hide themselves when you take the Vigilant Recycler perk - Optimized ammo is plain better (for this reason this mod now depends on GRA being installed as well as plain new vegas - if you really haven't bought the ultimate edition yet, go do it already)
Verified compatibility with A Tale of Two Wastelands - I have not run into any bugs, gameplay issues, or balance issues as a result of playing Tale of Two Wastelands with Extended Crafting loaded. It should be perfectly safe to use this mod with TTW.
---1.21 - Plasma grenade and pulse grenade recipes modified so that they're still viable after taking the vigilant recycler perk. Oops.

--Update 1.3
Added the ability to craft most of the 25mmG and 40mmG grenade rounds (this includes an overhaul of the old recipes for standard 25mmG and 40mmG, which were too difficult to make)
Added the ability to craft throwing knives and throwing spears
Added "Bottle Rocket" recipes (ability to make standard Red Glare ammo using alternate recipes)
Shuffled a couple of existing recipes to different crafting stations (some of them didn't make sense)
Probably a few other things I forgot.

--Update 1.4
Added recipes for Cateye and Steady (cateye isn't that useful in the default game, but some mods like Realistic Wasteland Lighting make it a life saver)
Added breakdowns to convert frag, plasma, and pulse mines into grenades
Fixed Sunset Sarsaparilla Bottle Rocket recipe to actually use empty sunset sarsaparilla bottles

--Update 1.5
Added a few new miscellaneous recipes
Added the ability to clone Sacred Datura Root from Salient Green
Added the ability to turn Datura Root into Salient Green - but only with the biological research station's guidance...
Added breakdowns for Dynamite, Powder Charges, and Satchel Charges
Added bulk ammo crafting recipes in multiples of typical clip sizes (example: 200 round belt, 5.56mm)
Added bulk breakdown recipes for standard ammo types
Added comprehensive recipes for working with .223 - you could easily use it as your primary ammo now
Added rebuild recipes for .38 special, .44 special, and .22LR plinking
Added the ability to convert .45 Auto cases to .44 Magnum cases and vice versa
Tweaked the naming conventions of all guns recipes added by this mod to improve overall presentation (there should not be any recipes taking more than one line to display, and sorting in general should be more intuitive to work with)

--Update 1.6
Added bulk breakdown recipe for BBs (meant to add it in 1.5 and forgot)
Added bulk ammo crafting recipes for Hand Loader ammo types
Added recipes to convert to/from salient green the following items: Apples, Pears, Potatoes, Carrots, Mutfruits, Crunchy Mutfruits (you can clone them anywhere, but processing them into salient green needs guidance from the biological research station)