I have that gun and it enjoy it very much, along with a few others. I have not been able to pattern mine for Turkey's yet... I am waiting on Willaim at Sumtoy to send me a replacement choke, as the 1st choke sent was made for another type of gun and did not fit. I purchased a Versa Max Pro=Bore choke from him that shot really well.
I have seen the patterns using a pattern master choke and Hevi 3.5" #5's in the A400 Xtreme and they were great.