OK, here is how I did the zero stops for my Leupold scopes. It is so simple I am surprised Leupold or someone else doesn't offer something like them.
Essentially, all you are making is a thin spacer that goes between the bottom of the readout knob, and the top of the scope underneath the readout knob.
At the local hardware store I bought a copper 3/4x1/2 pipe reducer. The 3/4 inch end just fits perfectly over the Leupold sight adjustment tower. Use a hacksaw to cut off a thin piece of the copper tube, usually between .1 and .02 inch. I have had to cut them thick then use sandpaper on a table, or a file and just rub the piece on it until it is the correct thickness. It is odd and fortuitous that this piece fits so perfectly.
To get the correct thickness will depend on where you zero your rifle, and how much down elevation is left under the turret. The less elevation left, the thinner the spacer that you will make. I would suggest starting out at around .07 inch thick and see if your adjustment turret will fit back on without any resistance on the allen screw that tightens the reading knob onto the turret. If there is any resistance to tightening the allen screw, the spacer needs to be thinner. Keep making it thinner until the screw goes on with no resistance.
You will need to allow between 10-22 clicks after zero to get it right. I made a couple that went just to zero, and they often jammed up and wouldn't allow proper adjustment. I found that I had to put in some slack to keep things working correctly. When properly made, your scope knobs get turned all the way to the bottom, then just come back up 10-20 clicks to the zero..
Like I said, it is so simple I'm surprised no one markets various sized shims to go under the turret for this purpose. Perhaps one of the companies that makes this sort of thing will take this idea, make the shims and sell a package of 5-10 different thicknesses. Then maybe they'll send me something to say thanks for the idea...
If I didn't explain it correctly, let me know and I'll try to clarify any hard to understand parts.