You will find the smokeless loads sold by firms such as RST are much gentler on the gun than black powder. Black is super if you want to be shooting old time loads for history's sake but otherwise smokeless.
Yes, I agree with Joe here on the low pressure smokeless loads being gentler on the gun.
You see, black powder is an explosive & that means as soon as it is ignited the whole charge goes bang at pretty near the same time. This causes an immediate pressure spike which tapers off quickly as the shot load moves off down the barrel.
On the other hand, smokeless powder is a progressive burn. Meaning that with the correct powder & load you do not have that pressure spike at ignition. More of a long gentle push all the way along behind the shot load.
My black powder loads rattle the china cabinet & glass doors inside the house while smokeless ones do not.
BANG verses whoomph.
O.M