I've seen this topic a few times recently where someone will shoot a few jacketed bullets after the lead ones to scrape out the lead and make cleaning easier.I'm posting this for newbies and please don't do this because it's counterproductive and if the leading is bad enough becomes dangerous as it increases pressure.This increased pressure is why Glock doesn't recommend lead in their poly bores-enough buildup and pressure rises to the point of a Kaboom.
Bullets have an ogive,the rounded part,and even SWCs have a rounded edge.While shooting jacketed will push some lead out it also compacts remaining lead into the bore.It may appear clean but there is still lead in the pores of the bore.Think of a pile of dirt or snow on the porch as the lead fouling and a shovel blade as the bullet.Pull the shovel back over the pile with downward pressure,you pull some of the snow off but compact the remaining.If you stand the blad at 90 degrees you will scrape it off,but requires more pressure.A full wadcutter would would scrape out the majority of the lead,but at the cost of increased pressure and you are still pounding some lead into the bore.This is an old wivestale that can be dangerous.
If you shoot lead,using the proper size bullet and hardness will leave very little lead.You have to slug the bore to find it's size,they are not all the same dimentions.9mm is one that can vary quite a bit,so once you know your bore size pick a bullet .001 larger of proper hardness with good lube and you'll be good if you don't push them too fast.Now,finding a company that will load an "off" size will take some searching if you don't reload.If you do reload there is an easy way to slug the bore with a custom built round but I do not recommend anyone try it without being a very experienced reloader and know powders and how they behave.Some powders behave quite scary at low charges and you're forcing a larger than normal bullet down the barrel,remember the pressure deal.
Cleaning lead out isn't hard,pure copper ChoreBoy wrapped over a brush will get the majority out,then soak with a lead solvent and patch out.
Another tidbit about cleaning.More barrels are wore out from over cleaning than actually shot out,with the exception of a few rifle calibers that will burn out a bore in a few thousand rounds.