I'm using a Chrony Beta Master and so far so good on it's working well. I did not get any powder blast,etc on it from shooting the rifle last time - but I did place it about 10ft from the muzzle.
Now when I used it for my cap & ball testing and only set it about 3to 4ft from the muzzle - MAN did I coat it in crud. It didn't do any damage to the unit, but it sure peppered the painted face of it though. When I saw that I just rigged up some cardboard in front of it and that did the trick..........except the skyscreen wires sure took a good "smoking". Fortunately, black powder residue is water soluable - so a quick wipe down had everything as clean as new.