Re: 20 Gauge reload question
What Terry said +1.
If your gun is shooting high, how high? Also, how are you mounting the gun and are you pointing or aiming.
if all three of your guns shoot the same (high) in equal parts, I suspect it is a shooter malfunction as opposed to a gun malfunction. Please understand I am not being flip or criticizing. I have had to have a lot of help with my shotgun when I began shooting clays. I have been a tactical shotgun shooter and instructor along with shooting tens of thousands of hi power rifle rounds over the years. So naturally I had to have an instructor help me.
It is very difficult to do much good for you at long distance, but I will tell you this in answer to your query.
!. It is not your load causing the gun to shoot high. I load almost exactly the same as you with either Universal or Unique and now I have two jugs of the 20/28 that Terry mentioned. These powders will neither cause you or your gun to shoot hi or low. And changing the load will not correct same.
If you can, take it to a range and shoot from a rest. Be as accurate with your sights as possible and see what the result is. Then stand, point at your target mounting the gn in the hollow of your shoulder, not on the point of th shoulder as a rifle would be mounted.
I believe you will then correct yourself.
Good luck, let us know the outcome, we all can learn.