I've been down that road, used Universal. I do have to warn you, some wads are not to be used in a straight walled case like the Cheddite or Federal. The Claybuster AA copy is the worst. It will not seal the powder, you will get squib(ish) loads and you may not notice the wad stuck in the end of the barrel. My load was 22 gr of Universal and 1 oz of shot.
I ended up using a BP Short sporting/field wad. I had so much fun both my 16's are in the safe, and they will probably stay there forever. Paying for overpriced 16 ga ammo, and/or the "fun" of loading them cured me of that. Don't get me wrong, love the 16, a fine gauge, but the ammo thing was too much for me. To further complicate things one of my guns had a 2 9/16 chamber. The final straw was when I couldn't roll crimp because the brass head would turn instead of the whole shell. It takes a lot to sour me, but I was soured.
The BP wad patterns well, then again it's not that hard to get a 16 to pattern well. My most memorable 16 ga shot was connecting on two huns with one shot, and my black lab doing a blind retrieve on the second. The distance, around 40 yards on the second bird. I just caught the bird tumbling out of the corner of my eye. The first retrieve was pretty standard stuff. Then, while Bella was sitting I said to her, "You know Bella, I think I got another one as well". She looked at me for a second, sniffed and went straight to it. She liked chicken as much as I do, so I had to hurry, not give her too much time to think, otherwise it would have been dog food.
Have fun with your 16.
RIP Bella.
