Hi

I have an Archers bulk fill cap for a QB78, I tried it on the front of my Crosman 600 and it was screwing on nicely but then started catching the barrel, As I didn't want to mark the barrel I stopped, I may reduce the outside dia of the cap by a few thou then re knurl it and have an other go!!

As the QB/XS78 are based upon the Crosman 160 I thought the threads would most likely be the same!!


John