I am shooting a Mossburg 835 3-1/2" with a h.s. undertaker choke. Anybody know of any good turkey loads I should be using? Here in Michigan I can not use anything smaller than #4 shot.

I suspect you mean you can't use any shot size larger than #4. #2, a smaller number, is a bigger shot size. That's the rule here in WI. Anything by Winchester is a good load.

I have the 535 and use the #6 3" federal free flight....I used the 3.5 last year in My Benneli Nova #5's. I have really liked the Federal shot. I used the Rems, Winch XX Blacks and Fichios??? and none did as well as the Feds

Im hooked on Federals 3in 5 or 6 shot. doesnt matter both shoot great...

I also use an 835 but with a Jellyhead choke. Ive had great results with Winchester Double-X Magnums, 3.5" 2.25oz #5's. Ive been told that nothing compares to Nitro shells, so im trying a box this year. Its probably too late to order them and get them in by MI's season opener. I also hunt in Michigan!

Try the Winchesters i mentioned, they work great.

If the undertaker can handle heavi shot I'd check out some Hevi-13s. A little more expensive but usually patterns much better than lead. Check out some 3" 2oz 6 and 3.5" 2.25 oz #6 and see what patterns better for you. They both will kill out way past 40 yards if the pattern is there.

I've tried nearly all the popular turkey loads in a variety of well known turkey guns and Hevi-13 loads have consistently proved to be the most impressive for us. I prefer the #6, but the #5's are also impressive shooters. Good luck and good shootin'