I shoot a Pattern Master in my A400 Xtreme with great results from Winchester Long Beards #5's & #6's. Also, I had great results with Hevi 5's & Winchester XR 6's (they don't make the XR's any longer). I haven't shot any other loads with the combo.
I have not tried a Sumtoy choke from William in it yet. I have 2 other chokes (Invector Plus & Remington Pro-bore) from William at Sumtoy and they work great in my Maxus & Versa Max.