Most cans I've seen had a date stamped on the bottom but this one isn't obvious. Is there anyway to determine it's age without cutting it in half and counting it's rings, like I do with trees? !
Regarding the pictured jerrycan, the letters and numbers on the line below USMC is the contract number.
The date will probably be the next line below the contract number.
I can't read an actual date from your photos, but it appears there is something below the contract number.
The under handle stamping on these cans are so faint, that a repaint often fills them in.
The stamped/embossed date is the surest way to determine age but...
WWII Army cans will have USA or U.S.A. on one side and QMC or Q.M.C. on the other, as do some early Korean War era cans before the switch to US on the side and no QMC about 1951-52.
U.S.M.C./USMC on the
side of the can stands for: United States Marine Corps.
U.S.N./USN on the side of the can = United States Navy.
US at the top of the side, and MC at the bottom of the side may indicate United States Medical Corp, but no proof has been found to my knowledge.
Aluminum cans with U.S.M.C./USMC on the side and an asymmetrical*
large mouth water can style lid, and CONCO with no date on the bottom have been witnessed in late 1950's photographs in service with the U.S. Marine Corps.
*There is a pouring spout molded into the lower portion of the opening versus a completely round opening.
Deviations, and exceptions occur of course with production on many different contracts with a variety of manufacturers.