In heaven, there are no guns. The purpose of guns is killing and God abhors killing and in so many words has said, “Do not kill.” A person will not enjoy the benefits of heaven by killing, and the meaning of killing, is ending the life of one of God’s Creatures. The creature could be one of the birds of the air, such as a duck, pheasant, quail, chicken, turkey, and so on. The creature could be living in the water, such as a whale, seal, tuna, salmon, and many thousands of other types of fish. The creature could also enjoy living on the land, such as a human, horse, cow, pig, elephant, tiger, deer, elk, bear, and many thousands of other varieties of air breathing animals.
A religious person following the doctrine of non-killing will be peaceful and friendly to other creatures and live on the fruits, vegetables, and legumes of the earth. A religious person wanting to enjoy the fruits of heaven must abide by the doctrine, but also, become a master of the meditations.
Here is a verse from the Veda about calling in peace and not injuring.
Suffer want or enjoy Heavenly Bliss,
And speak highly of calling in peace and not injuring.