Depends on how good the last guy hid it. I am reliably informed of one such being hidden sandwiched between two post-mounted sheetmetal advertising signs, not found until some passing [bored] GI decided to check his zero on the sign and got a resounding THUNK! instead of just the ping of a 5,56mm round zipping right through.
Remember kids, plinking at roadside signs CAN save your life....
Hey did ya ever link up with SLB at FT K ?