Gander,
If you are only getting 4 shots and the bore is getting tight,what do you think the problem is? I shoot all day long without wiping and definitely no "bore tightening"! Something's amiss.
If you are .535 land to land and you have 10 thou grooves,that means you are .555 groove to groove,no? Now, if you are using a .015 patch ( multiplied times 2).Now add .030 to the bore size. That gives you .565,correct? Which means you are getting only five thou compression in the grooves. Not enough for a rifle,me thinks.
What I would do is go to a .526 RB or a tad smaller(.520) and use a minimum .025 thou ,10 ounce denim patch. With 2f Goex,a good sloppy wet patch, you WILL shoot all day without wiping.( bore must not have ANY pits) Pits will snag your patch and all goes out the window.
All this two finger loading pressure is Hollywood Daniel Boone/Davy Crockett nonsense. Accurate rifles need compression to self clean and shoot accurately. No BS!