Inner Barrel Length: 510mm

As is standard in our high bullet valve design

High durability rubber material

Introducing the Classic Army X9 SMG - the first full metal

Elite Force Magazine Rebuild Kit for UMP Airsoft Pistols (Model: 2262046) mag Inner Barrel Length: 510mmBen Franklin forgot about leaky gas airsoft magazines when he said "nothing can be said to be certain, except death and taxes." Leaky gas airsoft magazines are a sure thing. At some point, it will happen, even if you own our exhilarating HK UMP GBB submachine gun. What happens when the inevitable occurs is entirely up to you. You can either toss that salvageable magazine in the trash (don't you dare!) or go pick up one of our HK UMP GBB Mag Rebuild