These 5.7 magazines can fit and function within standard AR-15 lower receiver so long as CMMG’s 5.7 conversion upper has been attached. If you already have CMMG’s 5.7 AR upper fitted, you are good to go! These mags will run reliably, feeding up to 40 rounds of 5.7×28 ammo before locking the bolt back after the last round is fired. This last round bolt hold-open ability was maintained by the great engineers at CMMG, and will allow faster mag swaps for those who are trained to utilize the last round bolt hold-open feature on most modern AR-15’s and magazines. Three magazines come in each order.
- 5.7x28mm – 40 Round Capacity
- Three Magazines Per Pack
- Fits Standard AR-15 Lower Receivers
- 8oz Unloaded Weight
- Black Polymer Construction