Ok so I picked up the tech pistol "Lizzie". It's a Rare/Iconic with 368 dps. If I go to craft the Epic version of it, it's DPS is only 223. Why does an epic version of the same gun have lower dps than the rare version? This seems to happen with a few other weapons aswell.

Also if I click the crafting spec for Lizzie about 10 times it's DPS goes up to 330? Also did this with a Katana. Base dps was 400, click the spec a few times and I can craft it at 700 dps. Wtf?

Check there's no mods on the weapon boosting it's damage, and also check your actual crafting skill is decent.

What I think is happening, based on what we're seeing, is that the random elements are being rolled in the background each time you select the blueprint and the DPS value is changing to reflect those.

Looking at Overwatch for example, I get either 268.5 or 360.3 DPS. It's pretty consistent, it won't change every click but when it does it just flips between those two values. The random damage type is the same in all cases (605 - 739) and the raw damage likewise (864-1056 with 0.28 attacks per second). So my guess is it's already determining the random stat and the random damage type when clicking the blueprint and modifying the DPS to reflect the output with those traits (in this instance for example it could be the Bonus Ricochet Damage stat, or it could just be there's a specific damage type I've got a bonus towards somewhere that's kicking it up when it rolls that type).

When I noticed something like this, it was a mod that boosted the armour of a pair of shoes WAAAAAY higher then anything I could make or find otherwise.

There is one roll for every time you look at a certain recipe.
But the damage is calculated taking in account the extra damage you can get from the "element".
Also remember that some weapons got a high attack speed but not really high damage per hit, so the calculations arent that off. Yeah, some mods come with pretty good rolls, remember to keep them (save them on your home) as there is a crafting skill (cant recall exactly on which level) that lets you disassemble objects and keep the mods.

another thing is that crafted items seem to rolled at your level, which I think applies the upgrade level based on your own. But some ingame items are fixed, not dynamically spawned. so fixed items (like any of the world legendaries, or "Hidden Gems" loot) may show up more powerful by default than you might craft at a lower level.

^whoops, multiple windows opened and I clicked post in the wrong one