I have owned many shotgun brands over the years and one thing I have found without a doubt that is true,not one of them will shoot the same brand of slug the same way twice.
mossbergs,winchesters,remingtons,brownings,any of them with a smooth bore barrel before the rifled slug chokes or barrels came out would shoot all over the board.
I found this out the hard way after sighting in a mossberg with remington one ounce sluggers and the next day of deer season I couldnt hit the wall of a barn from the inside and I missed my deer.
so back to the range at home,I was shooting the left over federals I had and I could not hit a one gallon antifreeze jug at fifty yards!!!
back to town and bought more rems,dead on as the day before deer season!! wth??
after learning from that one,each and every brand of shotgun there after was extensively tested with different brands and weights of slugs before any serious dialing in was done with sites.
I can honestly tell you IT DOES make a difference,once you have found the sweet spot with what ever brand,stick with it.
I am now down to two different slug guns,one shoots federal slugs dead on,and my 1100 shoots one ounce rem sluggers dead on,but I cannot mix and match between the two.
to your question,I am betting no more than two inches high at fifty yards difference with that A-5,after season,come down and we will dial it in!!