Just had a 9inch hushpower mod fitted to my 410 mossberg 3 shot bolt action . result is excellent , have tried it with 3inch carts and 2 inch carts and would say about the same level of noise not much more than an air rifle crack.Have not tried sub sonic carts as yet but will when i can get some.With my mossberg it has external choke so was lucky that the guy who fitted the mod for me managed to cut a thread in the mod so i can screw the mod off if i want to use it without the mod .