According to what Mossberg told me they have discontinued the SSI, not dropped it, for whatever that means. Suffice to say they have stopped making it, and barrels.
I have one in 30-06 and a rifled slug barrel also. The 06 shoots great average groups around 1.5 inches, haven't shot the slug barrel yet. The trigger was very heavy and gritty when I got mine but some polishing and smoothing with a Wyoming stone M_ke B__lm smoothed it us very nice. The gun is a little heavy for a single shot but is very well made and locks up tight. I like mine and will keep it, I'm looking for a 308 Win barrel, but haven't had any luck. I'll use it for blinds and tree stands where I won't have to walk a lot during the day.
Steve E..........