a good way to beat killing floor is to place c4 aling the north and east walls. place them far enough not to chain react. then go sit behind the box near the south west corner the ones placed in such a way that ther is only one entrance. snap the neck of any single soldier that comes by if two soldiers come allong detonate a c4 before they see you. all the soldiers wil go check out the c4 and you can hold them on the line till the time runes out.
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