I know this is an old thread,and this may sound far fetched but I've actually seen the c4 thing tried. A good friend of mine , a marine , was using the stuff during training. This was back in 1991. Somehow he found himself with some while on leave. He had completely stuffed a hollow point 12 gauge slug with the stuff. We shot it into a large tree and..... it didn't do a damn thing. I believe he only had one, and maybe the result would have been more dramatic if shot into steel or something completely solid but in that instance absolutely nothing happened accept a 12 gauge dia hole in a tree. If it could have caused the barrel to blow up in our faces(which I'm sure the possibilities were there) I guess once again god smiled down on idiots. That's been over 20yrs ago and I still wouldn't want to be the guy who saws up that tree. Talk about kick back!