The top is open so it can be loaded with stripper clips,,, (M-14)
And anything else that gravity happens to drop in.
~~~
And if you go prone you get your private little sand storm!
I never had a stoppage in combat(67-68),,,
You?...
Actually, my info came from a converation I had a long time ago with a guy who claims to have had two problems with the M-14 in combat. One was serious and involved a lost extractor. His second problem was temporary and was due to a wood splinter that fell into the action just as it was cycling.
That having been said, I have heard separate reports of M1-Garands, failing to chamber properly due to debris entering a cycling action.