It's just a poor quality picture. The slots are there with extreme magnification.
Printable View
Either way it sure is a post ban flash hinder.
How about this one as a replacement:
Attachment 122150
BEAR
One of the reasons for its success is the 1930s White gas expansion system finally perfected by SA engineer Earl Harvey. Lighter recoil and less wear on the parts. His own entry for adoption is second from the top on the left (his right). By all reports, it was an excellent gun.
Garand was aware of the White system but in the early days it was less reliable than the direct gas impingement method he used.
Attachment 122249
Oddly enough White's rifle looks like an M14-A2 with a little StG44 mixed in.