Dual ejection port firearm

Abstract

Firearms with improved systems and methods of controlling which side of the firearm shell casings are ejected from, with ejection port covers on both sides of the firearm that open to provide cross ventilation, or both. In some embodiments, the bolt can be installed in one of two different orientations to select whether shell casings are ejected from the left or the right ejection port without a need to replace any parts. In a number of embodiments, spring loaded ejection port covers on both sides open when the firearm is fired or when the bolt or carrier of the firearm moves to provide cross ventilation through a passageway through the firearm to cool the firearm. The covers can be manually closed by the operator when the weapon is not being fired to keep dirt and debris out of the firearm.

What is claimed is: 
     
         1 . A firearm comprising:
 a frame defining a bolt passage;   a bolt operable to reciprocate within the bolt passage; and   the bolt being rotationally symmetrical such that rotating it one half turn presents the same form as without rotation.   
     
     
         2 . The firearm of  claim 1  further comprising the bolt having a bolt face having a downwardly depending cartridge stripping surface, and a corresponding upwardly depending cartridge stripping surface, wherein the cartridge stripping surfaces are a pair of protrusions integral with, and radially spaced around, the bolt face, each having a flat front face that engages a rim of a top cartridge to be stripped from a magazine. 
     
     
         3 . The firearm of  claim 1  further comprising the bolt defining a central axis, and having an extractor positioned in lateral alignment with the axis. 
     
     
         4 . The firearm of  claim 4  wherein the downwardly depending cartridge stripping surface and the corresponding upwardly depending cartridge stripping surface are rotationally symmetrical with respect to one another.