I have gotten into cleaning the inside necks of my 308 brass for comp.Shooting..

I am using a brass bore brush with some 0000 steel wool wraped around the brush
and run it in a small battery operated drill...My question,is do you think this will
harm the brass,by taking out a bit of brass each time I clean them...

I have been doing some accuracy testing-and I think it helps to keep a more constent
bullet release upon fireing..And it also makes the cases size a lot easier as well,without
all the crud in there...Any thoughts on this? I know it just adds another step in brass
preperation...I suppose the only way to really tell is to get a new battery for my
chrony and take some readings...