Whisper....short version of CDS/M1 attributes/differences please.
Swaro and Zeiss offer similar mod possibilities?
CDS (Custom Dial System) is an option we offer on several VX-3, VX-R and now VX-2 models. It is a slightly elevated elevation turret. When you buy the scope at retail, it has the normal 1/4 MOA hash marks / clicks you are used to on any other scope. You will mount, boresight, and zero your rifle just as you would any other scope. Once you have determined the load you wish to shoot, you contact the Leupold custom shop to collect your free CDS dial. You will be asked, the caliber, bullet weight, ballistic co-efficient, muzzle velocity, elevation, temperature etc.... The more accurate and detailed you are with the information you feed the custom shop, the more accurate yoru dial will be. The custom shop will mail you the dial. There are three allen screws holding the generic dial that came with your scope in place. Loosen those three screws and the dial will lift up off of the post it sits on. Install your new custom dial, being sure to index it to your 200 yard zero. Tighten the screws and get to shooting..... The new dial will have a zero stop, so that you can always get back to your 200 yard zero in a hurry, even with out looking at the dial. This will limit you to one revolution, which should get most big game calibers out to about 700 yards. The one revolution thing is actually a good thing, as there is no way to get lost and loose count of how many revolutions you spun the dial.
The M1 dial is a tactical dial that we offer on our Mark 4 scopes. It is a much more agressive looking knurled dial. It is also a 1/4 MOA dial. It to can be laser engraved with the same custom dial information the CDS has. The major difference is that the M1 dial can reach out farther, due to the fact that it does not have a zero stop and you can dial more than one revolution. For those of you who shoot a lot and are in need of something that can get out to extreme ranges, this is a better choice than the CDS. Howver for most of us who are just looking to get out to 500 yards or so, the CDS is a much simpler and less expensive choice.
Also, we are currently offering a second free CDS dial with the purchase of any CDS scope through April.
Hope this helps.