I am a horticulturist not a physicist, hence the reason I am seeking your help. I am currently drilling holes in a certain species of tree using a regular electric drill. (I do this to insert a special treatment - to explain why I do this would take many more words!). The density of the green wood is around 720 kilograms per cubic meter. The size of the hole is 16mm diameter by 150mm deep. I am thinking that it would be a lot quicker if someone could develop a pneumatic tool similar to the captive bolt tool that is used to stun cattle during slaughter, whereby the tool is placed against the animal's forehead, or tree in this case, and a trigger is pulled to fire a bolt of dimensions 16mm circumference into the tree to produce a hole of depth 60 - 150mm depth (depending on the size of the tree). Alternatively the bolt could be hollow with the leading edge sharpened to cut a core into the tree, which is then removed when the hollower corer is pulled out. I mentioned this to a friend and he thought the tool would have to be very heavy (i.e. too heavy to work with in the tree) and/or the "kickback" would be a serious problem for the operator. So I wonder if any of you physicists can comment and suggest whether such a method would physically feasible? If I wanted someone to build a prototype for testing, can anybody suggest whom I should contact? Thanks in advance. Woodman.