PSA GEN4 4" 9mm 5" Lightweight Hex M-LOK Railed Upper With BCG & CH
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Palmetto State Armory
Overview
The PSA Gen4 4" 9mm Lightweight Hex M-Lok Railed Upper comes as a complete assembly, featuring a 4-inch barrel designed specifically for 9mm caliber cartridges, making it ideal for short-range engagements and compact builds. The upper receiver is compatible with the AR-15 platform, allowing builders to easily integrate it into their projects while benefiting from the versatility and modularity that the AR-15 is known for. This upper is commonly found in builds focused on personal defense and competition shooting due to its compact size and lightweight profile.
Specifications
PSA GEN4 4" 9mm 5" Lightweight Hex M-LOK Railed Upper With BCG & CH
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Build history on GunPartPicker
Builders have been adding the PSA GEN4 4" 9mm 5" Lightweight Hex M-LOK Railed Upper With BCG & CH to their builds on GunPartPicker since March 2026. All time, it ranks #620 of the 1,654 upper receivers builders have added.
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