| Term | Definition | Category |
| S | Striker Fired | Action |
| S&W | Smith & Wesson|Smith & Wesson Performance Center | Brand |
| SA | Semi-Automatic | Action |
| SA | Single Action | Handgun, Action |
| SAKO | Sako | Brand |
| SAS | SIG Anti-Snag | Item Description |
| SAV | Savage Arms | Brand |
| SB | SCCY Blue | Finish |
| SBRNZ | Bronze Nitron | Finish |
| SBS | Side by Side Shotgun | Action |
| SC | Scope | Item Description |
| SC | Sub Compact | Item Description |
| SCLPT | Sculpted Stock | Item Description |
| SCN CEN | Scandium Alloy Construction | Frame |
| SCP | Scope | Item Description |
| SCY | SCCY Industries | Brand |
| SE | Stainless Elite | Item Description |
| SER | Service | Item Description |
| SF | Speedfeed Stock | Item Description |
| SFTY | Safety | Item Description |
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