Cor, thanks for that, I really am most grateful. I had thought of making one myself based on the original end cap with a UNF thread attached (someone kindly offered to let me use his lathe), but I am quite happy to wait until JSR have one in stock again if i can't find one elsewhere. End of frequent reminders that the LGU is the loudest gun I have in sight at last! Incidentally, the end cap doesn't unscrew, it pushes in and is held by a grubscrew.