Ive shot bags of crows of up to 350 a time, the secret is flock covered decoys, i start with around 25, and you must have a perfect hide with high sides hide under as they will see you from at least afield away, if there high above circling around, there just looking, keep still because there not coming in, you need a good 32g shell to drop them as well, also be there just before light if you can as they start flying in the dark, and its important to nail as many as you can first thing, best of luck, crow shooting is a great sport.