That happens to be a problem with some of the BSA RED DOTS. I had the same thing happen to me. I ended up taking the RED DOT back. I use a Bushnell Trophy RED DOT because it has adjustable rings instead of a one piece base. Perhaps you could get a machine shop to make you a base cheaper then you could buy one. For .69.00 you can buy a Trophy RED DOT from Bushnell from time to time and sell the BSA.