my buddy has an 835 with the factory x-factor in it and his gun shoots extremely well with win hv 3.5 #6's and 5's and does pretty well with federal 3.5 2oz 5's... he never tried anything else because his numbers are good to go. since the 935 is over bored the same as the 835 try the factory choke with the wins. i am willing to bet you have a good combo right there. but if you want to boost performance. try and find you a star dot choke. they do not make them anymore but if you find one you will have gold in your hand. it will say it is for an 835 as they stopped production befor the 935 came out but both guns take the same chokes. get some fed hevi #7's or some hevi-13 #7's and you should be putting up around 250 in a 10 inch circle at 40 yds.