D/D In The Newer Pennies

CherryPickers' Guide isn't the right place to look unless they are major.

1983 D/D is possible, but 99% of the ones reported to me are split plating - not RPMs.
1993 D/D is impossible. Cannot happen.
1974 S/S minor RPMs are rather common, but so is Machine Doubling.
1931 D/D exists, but isn't much and wouldn't be something you would find int he CherryPickers' Guide.

Best thing is to get these coins to an attributer for examination.

You cant have a D/D on 1993 cents. Starting in 1990, mintmarks were not punched in by hand. They were a part of the die.

So you can't have a D/D after 1990.

If the whole coin is a doubled die such as the 1995 D DDO, then you would see doubling on the mintmark but there is also doubling on the date.

If the dates on your 1993 D cents are not visibly doubled then you have what Coppercoins suggests. Just something that looks doubled but is not a doubled die.

Thanks,
Bill

Forget about the term "master die cutting" - dies haven't been cut since the early 1800s.

What you probably have is a gas bubble (common), or corrosion (also common) but it's impossible to really tell without images.