Winchester AA-HS 20ga 2-3/4" once-fired hulls (100/bag)
The new style of Winchester AA hull (refered to as High Strength or "HS" by Winchester) is a three-piece Reifenhauser type design. It consists of a brass head, an inner tapered base resembling a plastic cup and a straight length of extruded plastic tubing.
The AAHS averages 2.7" in overall length. The distance from the mouth to the top edge of the inner-base cup is 1.9". This allows for a maximum wad length of 1.4" (with a 0.5" crimp depth) with a bit of wad compression. (Note: Wad compression does not consist of ramming the wad into the hull with thirty pounds (or more) pressure. Minor wad pressure of no more than ten pounds should be required.)
Winchester advises that the original Win AA and the new Win AAHS hulls are interchangeable. In the general sense of speed and pressure this may be true. However, there are some fit and finish concerns that require attention and different, accomodating components. At the base of the AAHS is a .020" thick rim edge where the inner-base cup meets the plastic tube. The ridge catches the gas seal of many types of wads, thus stopping the wad from progressing deeper into the hull. This prevents the gas seal from seating directly on the powder, which is required for proper load combustion. For this reason, the AAHS requires new loading information, outlined here with specific wad recommendations.
In BPI data:
"Win AA" or "Win AA-old" refers the the original, tapered AA hull
"Win AA-HS" refers to the new, three piece, High Strength hull
Similar new/primed hulls and load data options: