Recommended Crafting Loop
Step 1: Stockpile every single weapon with decent stat bars you come across.
Step 2: Pick the one you want to use, upgrade it to blue. If it doesn’t have a blessing and perk you’re satisfied with, scrap it, start over.
Step 3: Once you have that blue weapon with stats, one perk and one blessing you like, do not touch it.
Step 4: Buy mass amounts of weapons off Brunt’s armory. Upgrade them to blue and no farther, this is how you farm blessings. One heresy mission with books should be enough to bring one weapon from grey to blue.
Repeat until you unlock the second blessing you want to put on your weapon, upgrade said weapon.
You just have to get lucky, that’s about it. My best weapon on my veteran is a Graia BAG that I’ve had since before the game “launched” never found one yet with superior stats. Honestly, I wouldn’t spend a whole lot of time worrying about getting a perfect weapon. They’re going to introduce master crafted weapons (red) at some point, it can’t be that far off. I’d suggest you find a weapon you like using for now and save your resources.