Not familiar with an atomic rifle. There have been artillery pieces that can fire an atomic shell, but not a rifle.
The Henry rifle was invented by Hackman Adams.It was invented in 1860.
The first automatic rifle was invented in 1884. It was invented by Manuel Mondragon. The rifle was known as the Mondragon rifle later to be known as the M-1908.
The rifle was invented to let people aim and shoot guns farther.
Oliver Winchester invented the Winchester repeating rifle in 1860
The breech-loading rifle was invented by Captain Patrick Ferguson of Pitfours, Scotland, hence the Ferguson rifle.
Austria invented the first air rifle in the 1500's. The BB rifle was invented in the USA.
The bolt action rifle was invented by Scottish immigrant James Paris Lee.
It is believed that sniper rifles were invented around 1857 with the advent of the Enfield rifle. This rifle was then surpassed by the Whitworth rifle which became the first long range sniper rifle.
1860
1860
The atomic bomb that destroyed Nagasaki and Hiroshima, Japan.
The AK47 was invented by Mr.Kalishnakov, In the Soviet Union.