John, my Benelli housing was bought new and is less than a year old. I did call Surefire today and spoke to Craig in Customer Service.
He said they tested the bulbs to last up to 500 rnds. He recommended that during practice to take the bulb out to preserve it for actual usage. Surefire will send me a free replacement. I'm glad everything worked out. From now on I'll take the bulb out during practice.