i've gotten 200+ points several times now, and i still haven't unlocked pinpoint.

does it have to be in a specific game type, or a specific weapon, or just on a single person?

my first time was with using the shank, and my second and third times were getting lucky with a x2 and a level 2 cactus. each time involved more than one person.

 

It has to be done on a single Person and it can just be one number.

For example: Dualneedler x2, you deal 12*20 dmg= 240 dmg ----------- Wont unlock it.
Sniper crit, you deal 200 dmg ------------------------------- Unlocks it.

The number shown on the screen has to be 200+

 

Game is trolly sometimes,

Took me awhile to unlock 200 and 300 damage medals even with several single-shot 300+ hits so seems like it may bug out sometimes. Had a couple x2 crit snipers and got nothing (even for 200+ achieve), accepted 1 eventually, took a x2 Nuke crit for the 300+ achievement to pop up for me. :/