I filmed it with my Sony camcorder at night in front of my shop. I live in a rural area so there was no danger of anybody getting injured. We did it as follows, to get a decent focus on what was happening. I set the camera to manual focus while inside the shop at 5 paces. Then we went outside and I stepped off five paces from the shop so we was at the same distance and in focus. I had the camera at the 9 o'clock position and fired into a downed pine tree next to the shop. Well, when we watched the footage, I heard the round go off but thought the camera was not on me, until I watched it again with the living room lights off!! There was the smallest two little bitty sparks and if you don't pay close attention you wont see them at all. One was in the flutes and the other at the muzzle. I then used the "Nightshot" mode to see if it was any easier to see the flash. Well, it was a little larger, I am guessing from the infrared light in the heated gas. The nightvision flash was about the size of a 6 1/2 oz. coke bottle and shaped like on too, I had never seen one from this perspective before and didn't think it would make that much of a difference. This same rifle without any device on the muzzle had a 2 foot by 3 foot ball of fire at hte muzzle with the same ammo.
To answer the other question, I have two prototypes right now for 30cal that I am going to test, but I dont have one ready for production. I plan on testing them with my FAL and surplus GI ammo from South Africa.