Re: Primer interchange?????
Start at 36 and work your way up to 40 looking for pressure signs and accuracy, go up in .5 increments to 40, load 3 each of 36, 36.5, 37, 37.5, 38, 38.5, 39, 39.5, and 40. If you don't get signs of pressure start at 40 and work your way back in .3 increments until you find your most accurate and fastest load.
It's pretty common to use different components than the book lists, the bullet and powder need to be the same, but brass and primers will interchange at lower charge weights. Once you have your load don't try to switch brass or primers expecting the same load though, they will change things slightly, a different primer could make your good load bad, or your good load great, just something else to experiment with. They will change the pressure, so if are using close to max load a little hotter primer or a different brand of brass could boost the pressure up enough to put you over the top. Use what you have but always start low and work your way up, I like to look at 2 or 3 different sources for charge weights, they are usually a little different and you can get a good idea of what might work.