Here are some photos from 1985 showing
the penetrating power of Franchi's Metal-Piercing Shot when used in a SPAS-12.
I have little other information. It is obviously a Sabot round of
some type, made of Tungsten.
The entry hole of the MPS shot round in an 8 mm (0.310") thick steel plate.
The exit hole of the MPS shot round in an 8 mm (0.310") thick steel plate.
Four layers of bulletproof glass penetrated by Franchi MPS from a SPAS-12 shotgun.
1/20/00, Just found this:
From GURPS Contemporary Weapon Tables
Armor-Piercing Saboted (APS) Shotgun Slug:
+2 to Acc for shotguns equipped with
rifle sights (optional; +$50), DMG 5d+1(2). LC 1. 1/2D ×5, Max ×7, cost ×5.
Note: This round fires a sub-caliber saboted tungsten dart. Damage that penetrates is
not halved because of the large caliber. The dart will punch right through normal brick
walls, cars, heavy doors, and similar covers. (This is from a game).