A straight-pull action is one in which the bolt is moved straight back and forward to reload and cock, rather than the
up-back-forward-down sequence of the conventional bolt action.
The obvious advantage is speed of operation; because the reloading cycle requires only two movements rather than four,
a straight-pull rifle can be fired considerably faster than a conventional bolt-operated weapon.
Here I have examples of two straight pulls: the Austrian Styer M95 and two Swiss K-31.