The chart number of .145 for a 40gr lead round nose is almost exactly what I use (.146) for my SK Standard Plus after truing it both using LabRadar and targets out to 200yrd.
I saw a thread on here a few years ago stating .132 is a good number to use. I do and I agree, it seems to b pretty close to real world results when put into a ballistic calculator.
It's not the same BC, even with the exact same round out of the same box between two rifles with the same barrels. You might luck into it getting close, but you're still going to have to get real data for your rifle and ammo. With my Vudoo 20" MTU 1:16 barrel putting a good lot of SKRM though it, my BC is .158