Circulation Strike Verses Mint Strikes?

Pretty much the same quality until you hit the 2005-2010 uncirculated sets that had a matte finish different from the circulation strikes.

Cladboy, jbuck. It just so happens I'm looking through 2007 and 2008 unc sets, I didn't know about the satin finish. They are a lot nicer than older sets.

Jbuck pretty much nailed it.

Techniques to make mint set coins vary a little year to year but so do those used for circulation issues. But where dies used to make coins for circulation are allowed to be worn to a nub those used to make mint set coins are retired after ~40,000 strikes. Not only are strikes better in mint sets but they are made by new dies so more detail is usually visible.

The SMS coins from 1965 began this divergence in techniques for making sets. After the last SMS in '67 they continued using the same general techniques and presses to make mint set coins but without polishing the dies or planchets (usually).

The changes from year to year make this a very complex question but boiled down, new dies, lower speeds, higher pressure, and better handling simply makes finding Gems in mint sets like shooting fish in a barrel. Every year millions of Gems are made for circulation but finding them mixed in with billions of typical or substandard coins is very difficult. Finding them in mint sets is a breeze since about two mint sets out of three will have at least one Gem in it.

I believe earlier sets were just regular circulation strikes taken from the lines but they selected from the best runs. They set up a regular press with new dies and used the coins for mint sets. I have far less experience with these older mint sets (pre-'65) and there is even less information available about them! The mint has always been very very tight lipped about mint sets so they are virtually "secret coins". Until 1996 the mint actually maintained that there were absolutely no differences between mint sets and circulation issues but anyone who studied these sets could easily see the differences.

Now days there are almost no BU rolls or singles of the older clads anyway so it's a moot point. Now it's very hard to tell just how bad the coins made for circulation really were because they're all heavily worn. You look at one of these and think the detail is worn away when in actuality it was never there at all.