When exactly did the Marine Corps put the crossed rifles on the chevrons? I know what they stamd for, I just need a year or time period I think I've narrowed it down to some time between 1953 and about 1965.
Upon further investigation, I found this at the same site. It looks like they were using the crossed rifles before the 20th century too.
The rank of gunnery sergeant ('gunny') was created in 1898. By World War I it was used as the platoon sergeant rank, and was identified by crossed rifles and a flaming bomb.