I use these handles when working on shotgun furniture - I make them from scraps of wood to fit a specific action inlet ( there are tons of them in the workshop, although some handles will fit several types of furniture ). I can clamp the handle in the vice when chequering - and the hole in the end is for hanging the wood up when it's had a heavy coat of colour, or has been stained, painted or whatever.
For a rifle stock, I either leave it in the chequering cradle, or use a slimmed out broom handle that I've drilled a series of holes in that lines up with most of the popular actions I work on. Clamping it in the vice as above.