PSA GEN4 4" 9mm 5" Lightweight Hex M-LOK Railed Upper With BCG & CH
Click to see full view
Palmetto State Armory
Overview
The PSA Gen4 4" 9mm Lightweight Hex M-Lok Railed Upper is a complete upper receiver designed for the AR-15 platform, featuring a 4-inch barrel chambered in 5.56 NATO. This upper integrates a lightweight design with M-Lok rail systems for customizable accessory attachment, making it ideal for builders looking to enhance maneuverability while maintaining versatility. This configuration is often seen in compact builds focused on close-quarters performance and agility.
Specifications
PSA GEN4 4" 9mm 5" Lightweight Hex M-LOK Railed Upper With BCG & CH
Available Merchants
Price Alert
Log in to set a price alert on this product.
No Available merchants at this time.
Build history on GunPartPicker
Builders on GunPartPicker first added the PSA GEN4 4" 9mm 5" Lightweight Hex M-LOK Railed Upper With BCG & CH to a build in July 2026.
Updated · from real builds on GunPartPicker
Not sure which upper receiver to pick?
We ranked every upper receiver by how often it shows up in real builds on GunPartPicker.
Read the guide: Most Popular AR-15 Upper Receivers →Check it against the live catalog:
Frequently Built With
Popular alongside upper receivers on GunPartPicker
Aero Precision M4E1 Complete Lower Receiver W/MOE SL Grip & SL-S Carbine Stock
Aero Precision AR-15 Breach Charging Handle Ambidextrous Small Levers
Geissele Automatics AR-15 SSA-E X Lightning Bow Trigger
Bravo Company M16 Bolt Carrier Group Black
Magpul AFG-2 Angled Fore Grip - Black
Magpul AR-15 MOE Stock Collapsible Mil-Spec Black
No reviews yet. Be the first to review this product!