yes i have first handed tried my friend JG M4A1 and it shoots pretty hot out of the box... yes you mgiht want to replace bushings if there not metal and shim it that would be a great idea but my friend dint do that :S
and you might want to find a full metal good hopup its not so great... (
http://velocityarms.ca/index.php?mai...roducts_id=104 )
its on sale but i cant tell you if its good or not
but here some pics i took when my friend recived it
IMG_2017.JPG
IMG_2019.JPG
Yah i forgot to remove the plastic covering the box before i took the picture :S
IMG_2023.JPG
IMG_2020.JPG
IMG_2021.JPG