Soviet heavy SP guns

[Ratzki]

Yes, and no. First the yes, a higher velocity does flatten out trajectory, but you have to factor in the maximum penetration potential range of each gun. If you have a gun designed to be in it's maximum penetration potential range at 300m-1000m, then all targets within that range will be easier to hit due to the low trajectory of the shell at that range, not the velocity, and the sights will be zeroed in at this range. Now for the no, start shooting at longer and longer ranges and the trajectory increases as the penetration potential decreases. Plus, the trajectory curve is not perfect, it is flatter close to the muzzle and has a steep downward curve as the shell passes by the maximum penetration potential range. Also, high velocity usually means lighter round weight, and lighter rounds are influenced more by external factors such as wind ect. A low velocity gun might not have the long range penetration potential that a high velocity gun has, but the same rules apply. It's maximum penetration potential range might be 50m-200m with an AP round. At this range it's trajectory could be as flat as the high velocity gun is at greater range. If the sights are zeroed in at this range, then it too can be very accurate.
I handload as well and as Skeld mentioned back a bit, there is a whole lot more going on here then simple speed equals better hit chances. I think the reason high velocity guns hit more often is they can kill effectively farther away, so get better optical sights.