Hardwood bench dog with small bullet catch mechanism     
 

                              Somehow the idea of hardwood bench dogs appeals to me more than metal ones,
                  although I can use both interchangeably; above is a solid hardwood bench dog made
                  from 3/4 inch dowel stock. If you also use round bench dogs in your bench, select
                  dowel stock which is round and not slightly oblong or elliptical , this to ensure that
                  the bench dog fits the bench holes well. In my case, I have selected birch dowel rod. 
                  The spring-loaded bullet catch is press fit into a 1/4 in. hole.  The catch has a flange 
                  which is approx. 9/32 inch in diameter, the catch assembly is then pressed into the 
                  hole making for a solid fit with no need for glue. It is important to ensure the wider 
                  flange is not proud of the dowel rod, but instead forms a flush fit. This prevents 
                  any rubbing of the flange against the bench hole. 

                  You can either recess the bullet catch completely or file the edges of the bullet
                  catch flange a little. The length of the bench dog is variable and dependant on the 
                  thickness of your bench. Bullet catch placement is approx. 3/4 in. below the notch. 
                  To ensure positive locking of thinner stock, a raked flat notch was band sawed and 
                  then tuned with a chisel to provide a small angled rake, again this can be variable 
                  to suit your needs and thickness of your boards. I was reasonably surprised as to 
                  how well this works and I have since made a few of these. The 1/4 in. bullet catch 
                  is available from any fine woodworking hardware retailer, Lee Valley Tools in this case.