I use them, load them and have them.
I just used my standard 55gr bullet load I didn't change any thing because there tracer.
There tons of fun, even more when you have them for a pistol.
Just don't burn any thing that dosen't belong to you.
The biggest let down ever I had with them was when I shot a propane canister with one and nothing happened. I hit it perfect too, I hit the bottem of the tank where the metal base is welded on and it riped a all most 2 inch hole through the tank. Just a white puff.
They burn for about 6 seconds, I have shot plenty of them up in the air back home in Maine. You have to do 2 things, 1 know there arn't any houses for several miles down range (shoot them out over the sea) and 2 make sure there are no planes in the sky.
I load them for 223 and 5.7x28mm(FN).
They can rust your barrel a if you don't clean it after ward, or you can shoot some normal bullets to burn out the tracer crap left in the barrel..