Simple Buffer Particles Prefab to easily create shoot Particles that stay in the world, if you drag the Prefab in the World there is "SubEmitter" and "BufferParticleSpawner", in "SubEmitter" you can create your Particle that you need as example a shoot particle, if you now play the Particle System from "BufferParticleSpawner" the Particles of "SubEmitter" will be spawned and not deleted if you stop the "BufferParticleSpawner".