[WABishop]

I have a used Italian made Supre Tiger 61. I bench tested it the other night and found that when throttled all the way back it wouldn't shut off. When examimed there is a very very small gap in the barrel, the barrel doesn't rotate enough to close entirely. Has anyone noticed this? Am I doing something wrong? There is a stop screw threaded through the outer barrel that fits into a grove in the inner barrel, is the groove not long enough to allow the barrel to rotate enough?

Any help would be appreciated,

Thanks!