i got a AWT silencer for my rapid, it was for the 16" barrel,
put it on, tried to zero the scope......was fireing way high ajusted the scope fully still no joy.......looked like it was tampered with as the screws at the side of it were worn.....guy said it was new!! Hmmmm....anyway its on its way back, my advice buy it off the guys who sell them all the time i will be next time.....Rant Over
good luck les

ooh and £100 for a 19" barrel and silencer is a good price,