From dA:
 
Disclaimer: I do not condone the policies of Nazi Germany. This image is not intended to glorify the ideals or actions of the NSDAP and/or the Wehrmacht. Viewing, presenting and/or saving a copy of this image may be illegal in certain countries; the artist denies all liability for the viewer’s actions.
 
Yup. so this is the first in a series of either 5 or 6 images of the mane cast in WWII German uniforms. Why? Because hey, cool uniforms and guns! This is not about the politically incorrect implications. Mature warning (ideologically sensitive) because a lot of people will still be offended.
 
Applejack got chosen to represent the regular Grenadier, because she’s a no-nonsense, steadfast (to the point of being stubborn) and reliable earth pony. The weapon is a ponified Kar98k, with the rear sight moved forward to make it possible to aim by leaning the head down and sideways. The trigger guard is removed and the trigger enlarged to make it easier to operate with a hoof. No, it probably wouldn’t work regardless.