China Lake Grenade Launcher The China Lake Model ( or China Lake Pump - Action Grenade Launcher ) is a pump - action grenade launcher that was developed by the Special Projects Division of the China Lake Naval Weapons Center , which provided equipment to Navy SEALs . History . The M79 and XM148 grenade launchers were single - shot , and the repeating T148E1 grenade launcher was unreliable , so a request was made to China Lake engineers . SEAL Teams were pleased with the resultant pump - action grenade launcher , since the tubular magazine held three 40x46mm grenades , and so with one grenade in the chamber , four grenades could rapidly be fired before reloading . In fact , a skilled operator could fire four aimed shots before the first one landed . The grenade launcher was extremely light for its size , since a significant portion of it was made of aluminum . Despite this advantage in firepower , it did have limitations as it could not reliably feed the more oddly - shaped 40mm grenades . The pump - action grenade launcher featured leaf iron sights similar to the M79 . The front sight is a fixed square notch . Depending on if the leaf is folded or not , the rear square notch is either fixed or adjustable from 75 to 400 m in 25 m increments . Though meant for the SEAL Teams , a handful were used by Marine Force Recon and Army 5th Special Forces Group . Sources differ as to how many weapons were produced . One claims that between 20 and 30 were made . However , according to another source , only 16 were made . The highest original receiver number found is 50 , but it may never have been made into a functional weapon . Noted SEAL historian , Kevin Dockery has confirmed 22 completed guns being carried on Navy records . Currently , only 3 originals remain under US Navy control . It is sometimes mistakenly referred to as the EX - 41 or as the " China Lake NATIC " . The EX - 41 was a design concept created in the mid - 1980s based upon the earlier China Lake Model Pump 40mm . The EX - 41 was never actually produced , having never advanced beyond the conceptual drawing . No prototype was ever produced and it was a follow on design created a full 2 decades after the China Lake Model was produced . The China Lake NATIC designation is also erroneous as the weapon was never known by that designation . Since it was made on an ad hoc basis for special operations forces , it was not formally adopted and has no official designation . Thus the SEALs referred to the experimental weapon by referencing the facility which produced it , thus creating the name , " The China Lake Grenade Launcher " . All 4 remaining original China Lake Model grenade launchers are on display in museums . One , serial number 4 , is at the UDT / SEAL Museum in Fort Pierce , Florida while serial number 13 , is found in the War Remnants Museum ( Ho Chi Minh City ) in Vietnam . , Seial number 2 is stored at the US Navy Museum in Washington DC . One additional launcher is on limited display in highly restricted US Navy facilities at NSWC Crane . Improvements . An effort to produce an improved version of the weapon began in 1992 when Samuel " Dutch " Hillenburg , a firearms writer specializing in military weapons , teamed up with master machinist Brian Fauci . In 2003 , they achieved a breakthrough and were able to convince fellow writer and firearms enthusiast Captain Monty Mendenhall to finance their research effort . By 2004 , they had a functional prototype and had formed Trident Enterprises Ltd . to continue their work on the project . In June 2007 , a taping of an episode of the popular military technology program , " Weaponology " was filmed which announced that Trident had been approached by a U . S . company seeking to license their intellectual property in exchange for a royalty on each weapon produced . In October 2009 , the U . S . company had cancelled its contract to manufacture any variation of the launchers .