Oh yes, Gyrojet. I was hoping I'll find it there. Amazing piece of technology, and so badass when put beside bolters from Warhammer 40k, but it was described in

Oh yes, Gyrojet. I was hoping I'll find it there. Amazing piece of technology, and so badass when put beside bolters from Warhammer 40k, but it was described in the article quite inaccurately, according to my knowledge. > The rocket-bullet picked up speed only once it left the barrel, so the gun was useless at close range. But due to much less recoil and a maximum speed reached way, way outside the barrel, it had a potential to be much more accurate with much better terminal ballistics at long range, making it a great fit for rifles, except... > It also jammed frequently and was not very accurate. ...a fault in a production series was taken as a construction problem, so the Gyrojet was simply killed.