What type firearm???
We talking here, if a .22LR RECOMMEND that you pile some round bales together and get on top. As the .22LR will ricochet fired at a shallow angle to ground. Been there done that once!
Any .223 centerfire (hornet and above) will benefit from longer range capabilities and be safer to having any good down angle.
Or if you have a hillside to sit on and glass, even better.