Just got my new QD wetsides for my MP40's. Of course the first thing I had to do was disassemble them to see what the difference is. To my surprise they look just like a bigger version of my old MP10's. Is there more to it than that? I knew my MP10's were always more quiet than the MP40's (allowing for the difference in flow/size). They should be a little easier to clean and put back together again.
