Can anyone tell me what is a "Drop Shape" mast?

Mast with std diameter base that tapers quickly to be more like rdm (but not)...

Oh, so a hybrid? Standard base, thin otherwise.

Can it rig on a standard sail?

Yes. My main mast is a North Sting 30% drop shape, which I've used for 8/9 years, it seems to work with most sails (except any designed specifically for rdm). I don't think they have the increased wall thickness of rdm masts.

Used one for a long time on a Ka 5.8,you will have to adjust the cams a bit to fit, but it works well

I have an opportunity to buy a 430 XC55 and was hopeful that it would come to this.
No cams on my 5 and 6 m sails, so I'll contact the guy. Hopefully hasn't sold it yet.

Some booms (like a maui sails) can't clamp tight enough and a rdm shim is too small to fit so you may have to make some modifications i.e. adding a rubber sheath around mast making it thicker where boom connects.

I use a Radz drop shape with a Severne overdrive and are having problems with the top cam wearing a groove into the mast because the rollers are too wide for the mast.I am looking to see if I can purchase a smaller cam.

Good points guys.

Forgot about the boom. My smaller sails dont' have cams so no issue there.
I may re-think this as I already have a 30% carbon 430 which works well.

Thanks for saving me some money. Just brought in a sail and a 460 mast, and my wife is giving me an evil eye...

nbr You can fit a rdm cam to the top of the 3 battens and it works just fine with a North Platinum.

Ok I know Ill get red thumbed for this & I know Ive been told before but senility has kicked in..again.. whats RDM stand for? ( regular diameter mast..? )

RDM = reduced Diameter mast