I would also just ignore it when he strikes. My male spotnose was pissy for a while when I first got him, he would even try to bite me through his cage. After I started ignoring him and adapting a "I know your probably going to bite me but I don't care" attitude, he basically stopped. He still not a snake I would trust would trust with strangers or hold for long periods, but I can reach in and take him out without him striking. Yours is probably very stressed due to the poor conditions from before and being uprooted. Give him time, he'll come around.