Can't make particle loop

Hi everyone
I’m trying to make a particle loop.
I’ve tried two particle systems with the offset and two copies of emitter with the same offset. But nothing works.
There’s also a weird jump at the first frame which could be a reason why my loop doesn’t work.
Any ideas?
snow.blend (4.7 MB)

I found the cause of the problem. It’s a timestep. When I go lower then 0.01 - loop breaks. Next question - how to slow down particles without using the timestep?

If you zero out gravity and increase Mass to 100, adjusting the Normal velocity offers a measure of speed control. You may have to extend your particle lifetimes, however.