Cool but how does real life armor penetration translate to battletech damage?
It doesn't. RL penetration is pass/fail, not "sand away a layer at a time".
The L70's penetration gets worse at close range?
174mm at 500m vs 106mm at 2,000m...how did you figure that as worse?
BT is not a RL simulator, such as
Steel Panthers or the venerable
Angriff. RL simulators draw upon the wealth of measured data available for thousands of weapons to produce their tables, the data of armor thickness calculated to include angle of sloped designs and quality of alloys.