Load up a FPS template and move around. It appears the gun becomes grainy. This was tested on an NVIDIA Geforce GTX 980 Version 373.06 and a Quadro M4000.
Also tested on a AMD Radeon R9 290 @ Radeon Software Version 16.6.1 and the grainy textures do NOT appear.
Result: The gun textures become grainy and pixelly
Expected: The gun should not become pixelated and maintain high quality.
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-37362 in the post.