I have used it before with very good results (found at least 10 charges that are working good for different calibers). It might not give you the exact result, but it will put you close, shortening the search for proper combination of powder, oal etc. Its important to get all the variables as accurate as possible (case capacity, bore cross section area etc.) and adjust the burn rate (because it differs from lot to lol) and it should then match your bullet speed. Once there, table is pretty much accurate 
