Airsoft Upgrades

Hi-Capa HPA/MP5 adapter

Brand: Primary AirsoftCategory: HPA Guns1 retailer

Price: $134.99 — In stock at 1 retailer.

Prices last checked August 20, 2026 across 1 retailer.

This is a custom designed l aser sintered nylon adapter that allows you to use HPA (high pressure air) and Echo1/Cyma MP5 AEG magazines on your Hi-Capa airsoft pistol. To use it you will also need an MP5 AEG magazine, “paintball” tank with low pressure regulator (0-140) psi, a hose with a Foster (polarstar) quick disconnect and of course bbs. The normal operating pressure for green gas is roughly 120 psi depending on the temperature. We recommend that you run you pistol near this pressure and do not exceed 140 psi. Keep in mind that higher pressures can cause excessive wear and damage to the internal components of your airsoft pistol. I designed this adapter to even the playing field when playing airsoft with a pistol as a primary against AEGs with hi-cap mags. This adapter installs to your gas magazine just like our M4 adapter. Please watch the installation video on YouTube titled: Primary Airsoft adapter installation tutorial HPA and M4 Glock + Hi-capa https://youtu.be/AydmykdSGSM The adapter now comes with our new universal feed tube that will fit the following magazines: Tokyo Marui Hi-capa magazines 5.1 and 4.3 WE Tech/Armorer Works Hi-capa magazines 5.1 ONLY "long baseplate" ***(Our adapters do NOT fit WE Tech 4.3 magazines "short baseplate")*** Novritsch SSP1/KJ Works Hi-capa green gas magazines. Guarder light weight aluminum magazine bodies. The adapter will fit into a 4.3 Hi-capa with a 5.1 magazine because the grip is the same on both 5.1 and 4.3 Hi-Capas. The metal quick disconnect fitting in the photos will come installed. The fitting is a US standard Foster Pneumatics 1/8 NPT quick disconnect. The fitting can be changed to any fitting that has 1/8 NPT threads. Be sure not to cross thread the fitting when installing a different one. The adapter does not come with a gun, magazine or any other accessories. The plastic spacer can be used to short stroke your slide if you choose to use it. For the most consistent reliability we recommend you use the Echo1/Cy

Hi-Capa HPA/MP5 adapter price comparison: the lowest price is $134.99 at Primary Airsoft, and the median across 1 tracked listing is $134.99.

Compatible with: M4/AR, MP5, Hi-Capa, Glock, HPA, AEG

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Where to buy the Hi-Capa HPA/MP5 adapter: prices at 1 retailer

  • Primary Airsoft: $134.99 — In Stock

Frequently asked questions about the Hi-Capa HPA/MP5 adapter

How much does the Hi-Capa HPA/MP5 adapter cost?
The Hi-Capa HPA/MP5 adapter ranges from $134.99 across 1 retailer. The lowest current price is at Primary Airsoft. Prices are updated regularly from each store's live catalog.
Where can I buy the Hi-Capa HPA/MP5 adapter?
The Hi-Capa HPA/MP5 adapter is currently in stock at 1 retailer including Primary Airsoft. We track availability across 1 airsoft stores and update stock status regularly.
What is the Hi-Capa HPA/MP5 adapter compatible with?
M4/AR, MP5, Hi-Capa, Glock, HPA, AEG
Is the Hi-Capa HPA/MP5 adapter a good hpa guns upgrade?
The Hi-Capa HPA/MP5 adapter by Primary Airsoft is listed in our HPA Guns category and is priced from $134.99. We aggregate prices from 1 retailer so you can compare and find the best deal. Check the price comparison table above for current pricing from each store.

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