Zolanator 2000X Assault Rifle

The HYDRA Battle Rifle is a conventional bullpup battle rifle designed and developed by Arnim Zola.

Captain America: The First Avenger
The rifle was seen back in the 1940s issued to troops who served the Nazi deep science division known as HYDRA. It was seen in the hands of HYDRA troops who shot at prisoners freed by Captain America during his raid on a base in Europe. These same prisoners attacked the troops and confiscated some of these weapons, others confiscated the HYDRA Assault Rifle.

Upon their return, some prisoners like Bucky Barnes and Jim Morita were seen carrying this weapon. Later on when the Howling Commandos were on a mission to capture Dr. Zola, Bucky found himself ambushed by 2 HYDRA troops wielding the weapon.

Trivia

 * The HYDRA Battle Rifle is based around the AK variant known as the AKM.