Remington marketed clips for these rifles as they were sold, no special clip guides, just the cutout on the top of the receiver.
Apparently the cutouts supported the sides of the clip and it bottomed out on the back of the magazine. Not a great arrangement but it did apparently work.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.