Hello ,I'm looking to find some info on using Richard nakka's srm. Is there a way to change the nozzle throat size to match my motor? I tried using the nozzle erosion box but I'm not sure if that is the right way to do it. How accurate is srm ? I realize there are a lot of variables .but generally speaking if it calculates 25 lbs max thrust is that usually close to what it will measure on a test stand? The reason I ask is I'm building a test stand and I want to make sure I put the correct load cell on for my first test. Thanks, Dan