Re: What size Monopod?
First you need to figure what shooting you do the most. If you shoot uphill, get a shorter one. If you shoot downhill mostly, then get a taller one. Buy one according to what you need. But, for average use, just level your gun and measure how far it is from the bottom of the stock to the surface of whatever your gun is sitting one. Then, get a monopod that allows you adjustment both up and down.
So, if there is four inches between the stock and table. You would want one that allowed you to adjust from three inches to five inches ...... (well, you get the idea).