Never used one, but believe me when I tell you it is going to be VERY loud.....just look at the gills in the thing, and the angle the gasses will be directed by them!
http://primaryweapons.com/store/pc/catalog/PWS_PRC_5824_L_2.jpg
Ted
http://primaryweapons.com/store/pc/catalog/PWS_PRC_5824_L_2.jpg

Ted