12,7×99 Incendiary

[pzgr40]

Who can tell me the name of the 12,7×99 projectile on the right side of the picture, and if it' s WW2 either post WW2. The left one in the picture is the normal WW2 boat tail incendiary M1 for comparison.
Thanks in advance,
Regards, DJH

 

[nathanieljr]

Doesnt look like an M23, so I'd guess postwar, and possibly not American!

 

[pzgr40]

Found some info after a long search:
http://www.cartrology.com/browse-ammunition.php?Caliber=.50+BMG&page=13

page 13 , .50 BMG

Incendiary, M1 (Alt)

brass

United States

R A 42