like gun doc said, the noise may be the inner bark popping off. Inner bark looks kind of like beige paper stuck to the sap wood. if you have any leftover pieces of the locust, try scraping down through the layers to see what it's like .
I looked at your other threads and I applaud you for trying all this stuff at age 13- it's difficult stuff to learn . My suggestion is to find someone on this site and go (with your parents) to where they live and get them to answer some questions for you in person. A quick session with an experienced person will teach you more than we can with typed words. What state do you live in?
also, there are three stages to tillering: Floor tillering is where you judge the bend by pressing the tip on the floor. you only bend it about 6 inches during this stage. Next, you put on a string that is too long and start "real" tillering. this is where you pull the string and judge the bend . Never pull the string too hard- never pull it past your intended draw weight. the third stage is where you put on a string that is the correct length and continue "real" tillering.
good luck.