Look for this in the qc:
// 1 attachments
$attachment 0 "Base" 0.000000 100.000000 0.000000
Attachment0 is for the muzzle flash. Base is the bone the sprite is attached to (it moves and rotates with this bone). Numbers after that is the offset to put the attachment in the right position, set the numbers all to 0, and then put it in the right spot with trial and error.