The benchmark short M4 mid-cap airsoft magazine receives a precision performance upgrade with the PTS EPM1-S RX. Maintaining the compact 20R profile preferred by players seeking a low-profile setups and prone stability, the EPM1-S RX delivers an impressive 170-round BB capacity without the rattle of high-cap magazines.

The primary upgrade in the EPM1-S RX lies in its completely re-engineered internal shell tooling. Identified by its distinct grey polymer color and surface EPM1-S RX markings, the new internal housing features refined dimensional tolerances and a smoother internal BB channel. This design optimization ensures reliable, consistent feeding across high rate-of-fire AEG setups, housed within the battle-tested DuPont™ Zytel® high-strength outer shell.

Key Features

• Revised RX Internal Tooling: Features a brand-new grey internal shell with revised tooling dimensions, resulting in a smoother BB channel for unimpeded feeding performance.
• 170-Round Capacity in a 20R Profile: Delivers a dense 170-round capacity within a short-form factor magazine, eliminating spring noise while providing ample ammunition for extended engagements.
• Visual Fuel Gauge Window: Includes an orange mag level indicator that moves downwards as BBs are expended. Rests at the top when fully loaded and reaches the bottom when empty for immediate visual capacity checks.
• DuPont™ Zytel® High Performance Polymer: Constructed from ultra-durable DuPont™ Zytel® reinforced polymer to endure hard field use, drops, and rough tactical environments.
• Deranged Designs Enhanced Follower: Co-designed with Deranged Designs to maximize feeding speed and prevent BBs from slipping past the follower, effectively eliminating jams.
• Angled Basepad with Dot Matrix: The angled flat basepad allows shooters to rest the rifle on flat surfaces for enhanced shooting stability. Includes a front lip for easy pouch indexing and a dot matrix pattern for custom identification marking.
• Continuous Mag Well Guide: Seamless outer contours reduce snagging when drawing from pouches or inserting into rifle magazine wells.  

Technical Highlights:

• Brand: PTS EP Series
• Model: Enhanced Polymer Magazine 1-Short RX (EPM1-S RX)
• MPN: PT174450307 (Black) / PT174450313 (Dark Earth)  
• Material: DuPont™ Zytel® High Performance Reinforced Polymer (Grey Internal Shell)
• Dimensions: 140 x 72 x 26 mm
• Weight: Approx. 260g (Empty)
• Capacity: 170 Rounds
• Color Options: Black / Dark Earth
• Platform Compatibility: Designed for Version 2 based M4 / AR-15 AEGs, including:  
  • Tokyo Marui Style AR-15 AEGs  
  • KWA AR-15 AEG & ERG Series  
  • PTS ERG Series / PTS Masada / PTS PDR-C AEG
  • VFC AR-15 & HK416 AEG Series
  • Classic Army (CA) AR-15 & 416 AEG Series
  • G&P AR-15 AEG Series
  • AMOEBA AM Variants AEG
• Disclaimer: Intended for airsoft, training, and simulation purposes only.

Applications

• High Rate-of-Fire (ROF) Builds: Upgraded internal channel prevents feeding skips during rapid semi-auto or high-cycle full-auto shooting.
• CQB & Low-Profile Setups: Short 20R length keeps the rifle agile, avoiding snag hazards on lower obstructions.
• Prone & Supported Marksmanship: Resting the angled basepad directly on barriers or terrain provides a stable shooting platform.

FAQ

• Q: How can I tell if I have the updated EPM1-S RX version?
  • A: The EPM1-S RX internal shell is distinguished by its grey polymer color and "EPM1-S RX" surface markings visible when inspecting the internals.
• Q: Does the EPM1-S RX require a high-capacity speedloader?
  • A: Due to its strong spring tension and 170-round capacity, using a heavy-duty airsoft speedloader (such as an M4-style loader) is recommended for smooth loading.