Do you need Blueprints? Want to save resources on those grenades? then I got a solution for you!

My solution - UNCOVERED CACHE event! if you are new to the game (like myself) you want to take advantage of this event! they have websites that have maps that will tell you where these caches are, though, cache spawns are not guaranteed when the event is not happening, but they can still spawn. They also blow up after <x amount of time>, they play a ticking sound when you are nearby and I have found numerous blueprints in these - ranging from Heavy Gun Part BP, Wolfpack Grenade BP, Light Gun Part BP and Jolt Mine BP. You can also find Herbal bandages, weapons, grenades and basic parts.

Enjoy!