I should be able to come up with something that will work with the L96. Have suppressor and all needed parts at home now. And can do some small modding to the rifle if needed. So if you want to make a few or what not, let me know and I can test them out for you.
Like what was said earlier .... This may work due to the bb already being at speed when hitting the o-ring. I am thinking it may act like the choke on a rifle barrel.