AKsRul.e- several hundred rounds is nothing. Let me know after several thousand. At just under 1K I had to replace the trigger, it was worn bad enough it was doubling. The bolt release broke the first day I had it at the range. The cam pin was galled about the same time the trigger went. The gas key worked loose not too long after that. M1S is crap.
out of curiosity how many rounds did you fire that first range trip?
my 9mm from M1s has close to 2,000 rounds through it now with no sign of parts wear.
also, many people go with M1S or other parts kits distributers because they don't have the cash for high end ARs and 1,000 round range trips. several hundred rounds by most AR owner's standards is quite respectable. if you can afford to shoot several thousand rounds then you can also afford to buy a high tier AR instead of rolling your own from M1S.