Light is a couple years old. Purchased new in 2018 IIRC.
On the range today running my staccato with said x300. First round click, bang, broke and the x300 goes down. It lived on a g17 prior to this with no issues.
Light was mounted snug with no thread locker.
Given the rust on the cross bolt best guess is either the fastener was bad from the get go or it had developed a stress fracture and eventually weakened.
Surefire responded back with in two hours and is sending me replacement hardware for it at no charge so definitely good stuff from them.
Small world as I used a SF X300U-A last nite on my Staccato P-Duo w/ out issues in a night match but had to borrow the light back from a guy I just sold it to as it got replaced w/ an O-Light w/ a throw lever but no holster yet for it.
Back in the day SF was the standard by which others were judged but like everything other light manufacturers have caught up w/ them. I still have several SF lights as they just keep working & good to hear their CS responded quickly but they should, as that was also something you could count on back when paying the SF tax as I call it.
Congrats! You just discovered THE issue with the X300u-B model.
Not surprised SF shipped you one pronto; the bolt breakage is a ‘thing’ with these specific lights.
