Every 50 - 75 rounds, my auto disk will hang then then snap back with a PING. I read here of the recommendation to coat the disk and the slide plate with graphite. Would you recommend a dry powder like this?
http://www.amazon.com/Gunslick-Graphite-Lube-0-2--Ounce/dp/B000ZLVLCK/ref=sr_1_1?ie=UTF8&qid=1382879861&sr=8-1&keywords=graphite+lube
or a spray like this:
http://www.amazon.com/CRC-Graphite-Lube-Aerosol-Black/dp/B007I9XUD0/ref=sr_1_3?ie=UTF8&qid=1382879861&sr=8-3&keywords=graphite+lube

To me, the powder would not seem to be that much different than the ground up 700-x that is on the pieces now and the spray seems like it would make things sticky.

Thanks in advance.

I am using the spray on type. It was the only thing I could find locally. I have only used it once, but it seems to work pretty good. I found it at Home Depot for around $4.50 for a 5.5 oz. can. If you do get a spray, be sure to spray your parts over a trash can or outside etc., as the overspray gets on everything.
You also might want to look closely at your disks and slide plate to make sure there isn't any flash or gouges etc. causing roughness. It shouldn't be hanging up like that.

Lube the activation arms where it rotates in the body of the measure. One of mine was doing the same thing until I lubed it. Also check your hopper screws and make sure they're not binding up the disk. You want them snug so it doesn't leak but not so snug that it binds the disk up.

Also if the case is not centered in the shell holder the expander can sometimes hang on the case mouth and then suddenly "snap" in place causing the problem you describe. Ensure your cases are centered in the shell holder and that the shell holder is inserted all the way flush with the ram.

Thanks, guys.
Could be the screws are too tight. Either way, I will pull it, check for burrs, lube the disk and baseplate with spay and the linkages with wet oil.
That should do it.

Disk and base plate wont need any lube. They will get all the lube they need in the form of a graphite coating from running powder through them.

I tried this approach first. Have to say that mine worked better after spray on graphite lube from Home Depot.

Yup.