The Winchester SX3 Raniero Testa Special Edition differs from other versions of the semi-automatic shotgun only in terms of its features and accessories. Technically there are no fundamental differences.
The current WINCHESTER autoloaders in the SX3 series are gas-operated with a Dural-aluminum receiver.
In accordance with convention, the locking insert latches into the bolt carrier in the barrel extension above.
As is customary in current shotgun designs, WINCHESTER’s “Active Valve” piston system automatically adjusts the gas needed for repeating.
The Winchester SX3 Raniero Testa is chambered for 12/76 (12 – 3″) gauge and the barrel is accordingly marked ex works. Most of the other versions of the SX3 in 12 gauge also accept extra-long 12/89 (12 – 3 ½”).
The Winchester SX3 differs from the older SX2 series not only in the new stock design, but especially in its lightweight construction. This was accomplished by using an aluminum magazine tube and by keeping the barrel as lightweight as possible. The Winchester SX3 has a characteristically long and very slender forearm, especially for a piston-system, gas-operated autoloader.