Neighbor threatening to shoot a dog please help!!!

There is a male blue pit very young running around our road and we are in the middle of nowhere.
I have been feeding him but he just roams and we believe he was dumped but he killed two of my neighbors chickens today and tried to shoot the pup and missed but said next time he won’t miss.
Can someone please help this baby.
I would say he is maybe 6 months old.
The shelter is full and won’t take him.
He did good with my female dogs but not my males that is why I cannot bring him in.