Dardick tround
（重定向自Dardick）
![Patent drawing of open-chamber gun](/Images/godic/202501/07/Dardick_open_chamber_gun_pat_US2847784_fig25542.png")
![Patent drawing of tround](/Images/godic/202501/07/Dardick_tround_pat_2865126_fig45542.png")
![](/Images/godic/202501/07/Dardick_salvo_tround_pat_3855931_fig65542.png")
The Dardick tround, or simply tround (triangular round), is a unique firearms cartridge developed by inventor David Dardick for use in his open-chamber firearms. Named for its convex triangular shape, the tround allowed the firearm's chamber to be open on one side, removing the requirement for reciprocating motion when chambering and ejecting a cartridge.