I'd pair this with the "Kill 5 Flying Crows" Achievement. Although, you will get this one after shooting your 1st Crow.
You will find 2 Crows after you open the Castle Gate. Make sure you SAVE your game in the cabin next to the gate. (Where we found the first Gate Piece).
Scare the Crows. Shoot both while they are flying.
🏆"HUNTER" UNLOCKED🏆
Press Start > Restart
It will load you back at the typewriter. Walk back to the gate, place the pieces, enter the gate, and Kill the Crows again. Rinse and repeat until you have Shot 5 Flying Crows.
🏆"SQUAWK SHOT" UNLOCKED🏆
Video Guide: