After reading the responses I went back and checked the visibility range for the units in question and this is what the values were:
Soviet T-10M with a value of 20
Soviet T-54B with a value of 20
Soviet T-55 with a value of 20
Soviet ZSU-57 with a value of 10
One of my elite T-10M was able to "reach out" at a distance of 20-25 hexes to the dismay of 5 Chinese T-34/Type 58 tanks. Another group of 4 T-10M wasn't as gifted but they dispatched another group of Chinese vehicles at ranges of 12-15 hexes.
All of the T-54B/T-55 kills occurred at ranges of 10-15 hexes but one was scored at 21.
The ZSU is a veteran unit that has the luck of a cat in that I tend to use my ZSU's in AP/AT roles once the AI stops sending planes and of all the units this is the one that always draws tanks like a magnet. They'll pop out of the underbrush at 3-4 hexes only to get a dose of 57mm AT rounds and if they survive it's time to reverse...
The campaign I'm playing is Soviet vs China during the summer of 1958 and this battle was a meeting engagement. I've been rather lucky in spoon feeding my armor so that most of them have reached elite status but from the start I've kept a group of 4 BTR-40s whose only job is to save bailed tank crews.
Not sure if any of this will be useful but those of you who work on the code might or might not see something amiss.
Thanks for the responses!
Steve