The MasterPiece Arms 5770 MPA 20rd 5.7x28mm magazine for Defender is a purpose-built magazine designed specifically for the MasterPiece Arms Defender platform. Built from durable black polymer, this magazine holds 20 rounds of 5.7x28mm ammunition, making it a practical capacity choice for shooters running this modern defensive or range-focused platform. Whether you're building a magazine backup supply for regular range work or looking to standardize your magazine collection around the Defender, this MPA magazine delivers straightforward reliability in a lightweight, corrosion-resistant package.
Polymer construction keeps weight down and eliminates the corrosion concerns that come with steel, so your mags stay reliable whether they're seeing regular use or sitting in a range bag between outings. The 20-round capacity strikes a balance between practical reload intervals and manageable magazine bulk. If you run a Defender, having spares on hand is smart planning—whether you're at the range or in the field.
Designed to function seamlessly with MasterPiece Arms Defender firearms, this magazine is a direct-fit accessory that takes the guesswork out of compatibility. For anyone serious about their Defender setup, it's the logical choice.
| Magazine Capacity | 20 rounds |
| Caliber/Cartridge | 5.7x28mm |
| Material | Black polymer |
| Platform Compatibility | MasterPiece Arms Defender |
| Manufacturer | MasterPiece Arms |
| Model Number | 5770 |
Yes—this MPA magazine is designed specifically for the MasterPiece Arms Defender platform and is a direct fit.
This magazine holds 20 rounds of 5.7x28mm ammunition.
It's constructed from durable black polymer, which resists corrosion and keeps weight down compared to steel alternatives.
MasterPiece Arms
