The came with 28 and 30's. Also the grip is smaller so someone with small hand can reach the trigger. At one time I had both, teaching my Grandkids to shoot. Sold the 28 just have the 30 left.(and two more Grandkids) The one thing I don't care for, they are heavy.
I had one of each at the same time. Basically the stock on the micro is 7/8" shorter than the full size. My micro had a 34" barrel with matching # to the frame. I never could understand that one but it was 34". I still have some older Browning sales catalogs that show the available barrels. Mike.