The Alex Pro Firearms M4 Pistol is an AR-pattern semi-automatic pistol chambered in 5.56 NATO with an 11.5-inch barrel. It ships with an SBA3 pistol brace and a 30-round magazine. This is a limited production configuration identified by part number RI355. 
 

Key Specifications 

• Brand: Alex Pro Firearms 
• Model: M4 Pistol 
• Caliber: 5.56 NATO 
• Action: Semi Auto 
• Barrel Length: 11.5" 
• Capacity: 30+1 rounds 
• Color/Finish: Black 
   

Detailed Features 

• 11.5-inch barrel in pistol configuration 
• SBA3 pistol brace included 
• 30-round magazine included 
• Limited production run 
• Black finish

Owners of the APF M4 Pistol point to the SBA3 brace as a practical inclusion that makes the compact platform easier to control. The 11.5-inch barrel and 5.56 NATO chambering combination draws buyers who want a maneuverable AR-format firearm. Limited production status is seen as a selling point by some and a parts/support concern by others.

Build quality from Alex Pro Firearms gets mixed feedback. Fans describe solid mil-spec construction; critics note that fit and finish can vary between individual examples. The 30-round capacity is standard for the platform and does not generate particular comment.

Value opinions hinge on the limited-production angle. Buyers who prioritize the SBA3 brace and compact barrel length consider the M4 Pistol reasonably priced for the configuration. Those coming from high-volume AR brands sometimes find the APF name commands less resale value, which affects long-term cost calculations.