I was C for a very long time. When i first moved to Indiana, I didn't compete at all, but I still shot regularly ( I shoot at work fairly often). Last summer a co-worker sucked me back in.
I always had a few B classifiers, but never enough in a row. This weekend I went to a classifier special match, and except for a 39% (stupid no-shoots) and a 59.5% every other classifier I shot was easily a B, including one that was up around 75%.
I honestly think the biggest contributor was another shooter telling me that I moved and shot like an A shooter a few weeks ago.