yeah its the accurazy Im looking for
but I dont understand what you mean now , it cant be much more uniform than the fox balls
But what kind of accuracy are you looking for in a mortar? The Mortar is an area weapon.
This past week when Ernie and I were shooting my GB mortar we were aiming by eye ball. These mortars are only 7" to 8" long We stood back and by eyeball aimed the mortar by looking down the center line of the base and barrel and aligned it with the aim stake at 30 yards. When we fired we noticed while tracking the ball we could see the flight line was in alignment with the stake. When the balls impacted they impacted in line with the stake. The only exception was the full chamber loads and longer range. They had a higher altitude and always struck down wind of the line of sight.
We were loading with a volumetric measure and the balls of the volume charge always struck in the same general area, usually for with a foot or two of each other. Dispersion was varied more by up the range, down the range than windage right to left.
I reported these results from our shooting.
30 grains Fg sent the golf ball 10 yards.
40 grains FG- GB's went 20 to 35 yards.
45 grains FG-GB went 40 to 50 yards.
85 grains Fg-GB went 390 feet and few inches
85 grains FFFFG went 156 feet.
40 Grains FG steel ball went 10 yards
50 grains Fg steel balls went 20-25 yards
60 grains Fg steel balls went 40 yards.
85 grains Fg steel ball went 126 feet
85 grains FFFFG steel ball went 114 feet.
Those are roll out distances.
The 40 grain Gb loads were hitting at 20 yards. When we increased loads by 5 grains impact was 40 yards. A change of 5 grains by volume caused a 20 yard change in range. I think charge sizes are more critical than windage. Weight charges should increase accuracy vs volume loaded charges.
Golf balls and the Fox balls are very uniform. But if you start casting balls of zinc with varying diameters you also have to ensure the balls are uniform. That is what I am talking about.
Having shot the golf ball and pop can mortars a bit I don't really think there is any advantage to tight windage in the mortar.. Velocity is low and there is no real need for an increase in velocity. If you concentrate on keeping every aspect of the loading-shooting uniform accuracy will improve. I also believe if you increase range accuracy decreases as other factors.
If you game is range, how far can you shoot, then lesser windage might matter in the mortar.
The one best way I see to improve accuracy in a golf ball mortar is to figure out some way to get the projectile to stick when it hits.
Someone needs to test the windage theory. Build a mortar with minimum windage do some test firing and and the open the bore up a step and test again and see what happens. Windage for a 1.68 golf ball is .043. Do it it .004 increments. Who is going to do it?