Is Hunting with a Gun Prohibited?
Question

If I shoot a deer with a bullet fired from a rifle, and the deer dies, is it Lawful? If not what is the method to hunt by a rifle so that the animal is Lawful?
Praise be to Allah.If you shoot the deer with the rifle and mention the name of Allah, and hit the deer, and it dies from that shot, then it is lawful and it is permissible to eat it. If you catch up with it when it is still alive, it is essential that you slaughter it properly. 
Shaykh Ibn `Uthaymin (may Allah have mercy on him) was asked: Are the birds that we shoot with rifles and they died lawful or not? We find that some birds that we shoot have died before we can say the name of Allah over them. 
He replied: 
“Yes, if you shoot with a rifle when hunting birds or rabbits or deer, and you say the name of Allah when pulling the trigger, then it will be lawful, even if you find it already dead, because the Prophet (peace and blessings of Allah be upon him) said: “Whatever causes the blood to flow and the name of Allah has been mentioned over it, then eat.” And he said: “If you release your (hunting ) dog and mention the name of Allah over it, then eat.” But if it is still alive and able to move then you must slaughter it properly and mention the name of Allah over it when slaughtering it. If you do not do that and it dies, then it becomes prohibited for you. But attention must be paid to mentioning the name of Allah when pulling the trigger, because if you do not mention the name of Allah then it is prohibited to eat it, even if you forget, because the Prophet (peace and blessings of Allah be upon him) said: “Whatever causes the blood to flow and the name of Allah has been mentioned over it, then eat.” And he said: “Do not eat of that over which the name of Allah has not been mentioned.”(Fatawa Nur `ala Ad-Darb) 
Shaykh Ibn Baz (may Allah have mercy on him) was asked: Is it sufficient for me to say Bismillah wa Allahu Akbar when inserting bullets into the rifle when hunting , or must I mention the name of Allah when pulling the trigger of the rifle? 
He replied:
“What you must do is mention the name of Allah when shooting, and it is not sufficient to mention the name of Allah when putting the bullets into the rifle, because the Prophet (peace and blessings of Allah be upon him) said: “When you shoot your arrow, then mention the name of Allah” (Narrated by Al-Bukhari and Muslim, from the Hadith of `Adi ibn Hatim (may Allah be pleased with him); this version was narrated by Muslim)."(Fatawa Ash-Shaykh Ibn Baz  23/91) 
And Allah knows best.