All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
Muslim jurist have differed in their rulings regarding hunting with a gun. Some consider it similar to the "Muaradh," which is an instrument that combines wood and iron. If the animal is hit by its edge, it becomes permissible to eat, but if it is hit by its flat side, it is prohibited, just like the "Mawqouda," which is an animal that dies when struck by a stick, stone, or a heavy object. This is because the gun's impact crushes and kills the prey due to its weight. If the prey is still alive when found, it must be properly slaughtered and the name of Allah (Tasmiyah) should be mentioned on it to make it permissible for consumption. Both the Shafi'i and Hanafi schools of thought have adopted this viewpoint.
The hunted prey that is killed by a weapon that has no edge is not permissible to eat, even if it is wounded. Imam al-Nawawi, may Allah have mercy on him, said in his book [Al-Majmu' Sharh al-Muhadhdhab, 9/110]: "If one throws a weapon that has an edge like a sword, spear, or an arrow and hits the prey with its edge, and it kills the prey, then it becomes permissible to eat. However, if one throws a weapon that has no edge like a gun - meaning clay pellets of the size of a hazelnut - or a pin, or anything that has an edge, and hits the prey with it, and it kills the prey, then it is not permissible to eat."
According to the Shafi'i school of thought, one of the conditions for a hunting instrument is that it must be an edged tool capable of wounding the prey. It is not permissible if it is a bludgeon because it does not kill with its edge. Similarly, using iron-made tools thrown with fire is prohibited. It is mentioned in [Fath al-Mu'in bi Sharh Qurrat al-'Ayn bi Mahasim al-Din (p. 306)]: "It is absolutely forbidden to hunt with the usual gun, which is made of iron and thrown with fire because it burns and crushes rapidly."
The Shafi'i school of thought permits hunting with a gun and bullets if the hunted animal does not usually die instantly from the shot, like ducks for example. If the animal dies instantly, like birds, then it becomes impermissible (haram) to consume. However, if the animal is killed instantly due to the power of the shot or the shot cut its neck, it becomes impermissible to eat.
It is stated in [Hashiyat Qalyubi and Umaira, 4/245]: "It is permissible to hunt with a gun in cases where the hunted animal does not die instantly from the shot. Otherwise, it becomes impermissible (haram) to consume, as is the case with birds (like sparrows). The use of a gun includes cases where it involves fire or not, and it is just an example. Therefore, any bludgeon that causes instant death, like a gun, falls under the same ruling."
The Hanafi jurists stipulate that for hunting with a gun to be permissible, the hunted animal must experience a rupture of blood from the wound. It is mentioned in [Hashiyat Ibn Abidin 'Ala al-Durr al-Mukhtar, 6/471]: "Qadi Khan said: It is not permissible to hunt with a firearm, stone, bludgeon, or anything similar, even if it wounds the animal. This is because it does not pierce unless it is something like an arrow, which has a point and length and can be thrown. If this is the case and it punctures the animal, then its consumption becomes permissible. However, a wound that only strikes the surface and does not pierce through completely is not permissible to consume because it does not lead to the rupture of blood. Both iron and non-iron bludgeons are the same in this regard. If the wound leads to rupture, then it becomes permissible; otherwise, it is not."
Some jurists, including the Maliki school, consider bullets to be sharp instruments that pierce through the body and cause bleeding, thus killing the animal by the cutting effect rather than just the impact. According to this view, hunting with bullets is permissible. It is mentioned in [al-Sharh al-Kabir by Sheikh al-Dardir, 2/103]: "The matter of hunting with bullet guns has no explicit precedent among early scholars, as the use of gunpowder in firearms emerged in around 800 Hijri. However, later scholars have differed on this issue. Some of them prohibited it by analogy with clay pellets, while others allowed it, such as Abu Abdullah al-Qurri, Ibn Ghazi, Sheikh al-Munjur, Sidi Abdelrahman al-Fasi, and Sheikh Abdelqader al-Fasi. They argued that it is permissible due to its effectiveness and quick action, which serves the purpose for which Islamic slaughtering was prescribed. Comparing it to clay pellets isn`t valid because they lack the penetration and perforation found in bullets, and bullets are not included in the prohibition mentioned in the Quran where the animal is struck by a stick, stone, or a heavy object."
Based on this view, if the condition of hunting is met with bullets being sharp and capable of causing cutting or perforation that affects the flesh, then hunting with bullets is permissible, and the animal becomes permissible (Halal) to eat. If the condition is not met, then the animal would not be halal for consumption unless properly slaughtered. However, there is no sin in adopting the opinion of the Maliki School in this regard. And Allah the Almighty knows best.