I start with a lead plug, poured by putting a wooden dowel about three inches into the (well oiled ) bore with a piece of 10/32 all thread in the dowel sticking out of the bore.(I hold it in place by building up a tight fit with masking tape). I then pour about 1 inch of lead in, let cool and then pull out and remove the wooden dowel. I then take a hacksaw blade and cut the grooves of the plug deeper( They match the lands of the bore ). Then I use a disposable ramrod with a bore protector and valve grinding compound to lap the barrel. I like to use about 100 strokes all of the way. Then repeat the process with a new plug and lap the bottom third again, then the bottom 2/3. . I try to give the barrel a slight "choke" effect to make loading easier.. I find that most of the pitting is in the grooves so I try to lap the grooves with out enlarging the bore lands. Once you get used to it it only takes about three hours to do a barrel.You want to make sure you use a bore protector to protect the crown and very end of the barrel.The ramrod will get the compound embedded into it so You don't want to use it for any thing except lapping.