Abstract: A relatively simple repeating firearm is disclosed which includes a sliding bolt which is removably housed within a firearm housing and which is biased into a bullet loading and firing position by means of springs provided in an overlapping fashion with a longitudinal extent of the bolt to thereby reduce the overall length of the firearm. A short stroke for the sliding bolt is provided to enable a rapid firing of the firearm. The sliding bolt and firing mechanism contained thereon are easily removed from the housing by a removable rear cover with the firearm accommodating different calibers of bullets by replacement of the sliding bolt as well as a removable barrel which contains the firing chamber therein.