Can't help you there. I don't have a mini. My guess would be that the Tactical Master Mini has the same insert as the Combat Master Mini, although their lengths are listed as 5" (on Amazon) and 4" (on Spec Ops website) respectively. Spec Ops doesn't have the Tactical Master on its website, and the description on Amazon says it's really more like 4 1/2 inches. I suspect the Combat Master Mini is also really about 4 1/2 inches because their other sheaths will hold a knife a little longer than advertised. I think either one would probably fit a 4 1/2 inch SOB, but I don't know that it would. Perhaps someone who owns a Mini will chime in.