If a guy doesn't push the limits or try to hotrod old guns to their maximum loads then all the worries about minor deviations of scale calibration, powder testing, etc., etc. Don't come into play. Using mild charges of slow burning powders at BP levels wont be any more dangerous than BP loads in a Ballard action. Minor variations in powder charges might affect accuracy, but no more than minor variations in BP charges, and both will be safe.
The advantages of smokeless for myself are many. First off no wiping between shots at the range. I can shoot all week and never wipe my bores. Second my BP loads take me a lot of time, and a lot more steps to make up very accurate BP loads. I can make up 5 rounds of smokeless ammo in the time it takes me to make one round of BP ammo for a match. Cleaning for a single shot is indeed easy with BP, but must be done fairly soon; and the same applies to brass. I can leave my smokeless brass for years if I wanted to and no harm done. BP brass I drop in a milk jug with soapy water at the range, and clean it as soon as possible when I get home.
My rifles shooting BP get wiped after each shot, but once I get home I thoroughly clean the bores, and actions. Powder can and does drop into the action when extracting cases, and it can corrode where you don't see it inside. So I clean actions and bores well. Something I don't worry about with smokeless loads.
I'm not going to tell you that you need to shoot smokeless loads, just that it's not a necessity to shoot BP loads to make it safe to shoot a Ballard.
