The problem with using the ballistic calculators generally available is that the data is based on available pellets so you end up comparing different designs at the different calibres. Even when the pellets are called the same they are usually different designs which will affect your results.

It depends what you want to get from the results. If you just want to compare the different calibres with available pellets then obviously you can use things like Chairgun but the answer you get can be anything you want depending on the pellets you choose. If you want to compare the calibres firing identical pellet designs then you need different software not generally available.