REAR STOCK ELEVATOR

[Shepard]

Check out this part.

http://www.riflestock.com/store/do/product/RAC/24-09-01

[iridium-192]

Good price for this thing.
Here is what I would change though basing on my own experience - while you adjust it (up & down) a stock will do circle movements on a bench & you will be tired to readjust a rifle trying to find a target... So that adjusting wheel must be much smaller (a diameter) & best of all if it would have a point so while adjusting it the rifle would stay in place. In the same time it should be ridged enough to withstand multiple rapid movements during recoil & of course dull enough not to scratch a bench... A ball point would be the best option... (That's what I intend to do in following projects)
I hope it does make sense