Even if I needed to put a fence around the appliance for 5 holes in relatively sandy soil, I do not know how long I would have taken with pick and shovel. In addition, the hole for a fence post must not be so wide that by neighbor's perfect. The processing is to be described in one word: massive. Surface with massive stones but will probably also this drill reach its limits, simply because you need then to turn a lot of power and also snail nat. also can not solve every stone.