Grading

Welcome to the forum.

No, it wouldn't be fair to grade them like that. In fact most of a roll of quarters usually won't make MS 65 and it's a fine day indeed when you get half a dozen MS 66 coins out of a whole BOX of new quarters. I've gone through multiple boxes of new quarters looking for a single cherry in high 66/67 and been disappointed.

Basically grading works on individual coins, an evaluation of their fields and designs, the overall strike and so on.

It's impossible to mass grade a group of quarters, especially in that high a grade.

I was gentle. ;)

That question arises a lot. In my opinion;

The easiest way to learn to grade is to buy a series of coins in the years you are trying to learn that have been already graded. In your case, if you get just some graded samples of a 1999 variant (I'd get June, right balance of design and empty fields) you will have a benchmark for that type of quarter. So you buy the same coin in MS-64, MS 65 and an MS 66 all of which can be obtained for reasonable money and you will have real samples that may help you.

These are grading aids that when combined with the variety of grading books will help you learn to grade coins - something that will serve you well as long as you are dealing with coins.

Open a brand new roll of coins, and just sort them individually, from best to worse 'mint state condition'. Then repeat this process for an additional, identical roll. Take the top four from each roll, and set them aside (we'll discuss those later).

So, the remaining coins: the worst condition coins in your sorted piles, while brand new, are MS-60. The best ones, excluding those you set aside, are probably 'nice' MS-63 grades. The remainder are probably from MS-60 to MS-63, but study and compare those to the worst ones you identified, and the nicer ones. You will get an eye for the 'baggy' MS-60 coins, the nicer MS-63 coins, and coins too nice to be MS-60, but not nice enough for MS-63 - therefore MS-62 grade.

Now, back to those top 8 coins, the net from two rolls. Roll the coins under the light, if you see more than three marks or tiny imperfections with your naked eye, then, put those coins into the MS-63 pile. If you see only a mark or two, then you will need at least a 6x lens or loupe, to carefully examine the coin's surface. Examine both sides, but bear in mind that the obverse carries greater weight for the net grade. Then, it depends where those marks occur (in the hair versus the cheek for the devices - in the fields in the legend versus in the fields in front of the portrait). If you can only identify a minor mark on the obverse with a 6x lens, then you might have a MS-65. Anything more goes in the MS-64 pile. An MS-66 coin will appear to be almost perfect, and as ugly stated, you would be lucky to find one in 5 rolls, and typically one in half a box, depending on the batch of coins you receive.

The only way to learn how to grade modern mint state coins, is to start cracking open brand new rolls, and sorting in relative terms until you are comfortable enough to assign numeric grades. Good luck.