Torture Test: U.S. Ordnance MAG-58/M240

Torture Test: U.S. Ordnance MAG-58/M240


Mix n’ Match
One of the best ways to check on a production line Quality Control, is to switch out the parts on different units and test them out. Interchangeability is critical in a machine gun, and it was decided to do this test at the indoor range at U.S. Ordnance. LMO’s Chief Armorer Instructor Matt Babb selected 4 machine guns from the production line, and along with the Armory staff at U.S. Ordnance, took them to the indoor range. Several hundred rounds were fired from each of the 4 randomly selected M240s. After firing, the weapons were taken to a large workbench and the 4 guns were stripped to component parts. The parts were placed into a large pile and then parts were randomly selected out to create 4 machine guns. The weapons were assembled and the belts prepared. Another 200 rounds were fired from each machine gun. No stoppages were encountered at all. This is what was expected from a combat production weapon, that the parts will interchange and function without fitting or modification. U.S. Ordnance has over 15 years experience as a company, and the management/engineering team has experience going back to the 1970s, so this was no surprise, and indicated customers can have confidence in these weapons regarding the supply chain. Parts to U.S. Ordnance guns will work in any of their production weapons.

Jessie Cunnally (U.S. Ordnance) test firing weapon after interchange test at U.S. Ordnance’s indoor range.

Barrel Test – Dispersion
In addition to testing of 100 rounds per minute at intervals and 200 rounds per minute in sustained fire, there is a new test called “Hasty Defense.” This new protocol that U.S.MC and Big Army are planning to implement is 1 minute firing at the cyclic rate of the weapon. In the case of the M240B, that would be a 650 round continuous burst, and for the MAG-58, more like 750-800 rounds. Whatever is involved, it has to go full cyclic for 60 seconds. Fortunately, the MAG-58 design can do that very well. Barrels will need to pass this test, with multiple passes and tests for decay in dispersion. We thought it prudent to include this test in the protocol.

The “Hasty Defense” test was fired separately from the main test, since it would break into the protocol we were observing. Three barrels that were chosen for this test were one U.S. issued M240 chrome-lined barrel, one U.S. Ordnance manufactured chrome-lined M240 barrel, and a special U.S. Ordnance stellite-lined M240 barrel. Because of their work with the M60 series machine guns and M2HB machine guns, U.S. Ordnance has stellite lining capability in-house.

The test is designed to see how the weapon performs overall, but there is a special point, especially to the “Hasty Defense” test: finding out what the effect is of wear on Barrel Dispersion. Put more simply, do you continue to reliably hit the target as the barrel is worn in?

The three barrels chosen all performed quite well. The surprise, and perhaps a signal that U.S. Ordnance has “a winner” in their barrel, was the Stellite-lined barrel. After 15,000 rounds and several “Hasty Defense,” “Mad Minutes,” there was no deterioration in accuracy at all. The machine gun was locked down, and the accuracy at the end of the test can be clearly seen in the target picture.

Matt Babb (LMO) and Dan Fassler (U.S. Ordnance) endurance test firing.

U.S. Ordnance stellite-lined barrel accuracy test.