Period-156 glider gun is a glider gun with 8 barrels that was found by Jason Summers on October 28, 2004.[1] The oscillator Jason's p156 is basically this gun with all glider streams blocked. In terms of its 36 cells it is the same size as the Gosper glider gun, but the Simkin glider gun is still smaller at 29 cells. It is capable of pulling beacons.
A suppressed form of the gun appeared semi-naturally on September 22, 2018, in a soup submitted by carybe, forming a period-312oscillator, the highest-period oscillator to have occurred semi-naturally.[6]