The ProMag MKA 1919 is a semi-automatic shotgun chambered in 12 gauge. It is designed to resemble the AR-15 platform and offers a detachable box magazine system for quick reloading. While the MKA 1919 typically comes with a 5-round magazine, ProMag does manufacture an extended 10-round magazine for this shotgun.The ProMag MKA 1919 10-round magazine allows for increased ammunition capacity and can be useful for those looking for extended shooting sessions without having to reload as frequently. It is important to note that availability and compatibility of ProMag magazines can vary, so it is advisable to check with reputable firearm accessory retailers to ensure you are purchasing the correct magazine for your specific MKA 1919 shotgun.

As always, be sure to comply with local laws and regulations regarding magazine capacity and modifications to firearms.