The Orthos Arms Raider S4 is a semi-automatic 12-gauge tactical shotgun with an 18.5-inch barrel, 3-inch chamber, and a 6+1 round capacity. It has an M-LOK forend and comes in black. 
 

Key Specifications 

• Brand: Orthos Arms 
• Model: Raider S4 
• Caliber: 12 Gauge 
• Action: Semi Auto 
• Capacity: 6+1 rounds 
• Barrel Length: 18.5 inches 
• Color/Finish: Black 
   

Detailed Features 

• M-LOK forend for accessory attachment 
• 3-inch chamber 
• 18.5-inch barrel in a compact tactical package 
• 6+1 capacity 
• Semi-automatic action

The Raider S4 is a newer entry from Orthos Arms, and owner feedback is still accumulating. Early buyers report the M-LOK forend as a practical feature that makes light and sling attachment straightforward without aftermarket modification.

The 6+1 capacity and 18.5-inch barrel combination draws favorable comments from home-defense oriented buyers. A few owners note the brand is unfamiliar and that the lack of an established service network is worth factoring in before purchase.

Cycling reliability with buckshot and slug loads appears consistent in early reports. Some owners flag that the Raider S4 needs a break-in period before it runs lighter field loads cleanly, which is common in this class of semi-automatic tactical shotgun.