Below is some information to help wind up the discussion about the subject of ten shot groups at 100 yards.
For those who wish a summarized version, see the last two sentences.
I shot a considerable number of targets with three ten-shot groups between August 4 and August 18 last month. Many of them were shot during days when the area in which I live experienced a rather prolonged period of very calm conditions, particularly in the mornings. When it became breezier, results were often much less consistent and predictable.
Over 53 targets with three ten-shot groups, shot with different lots of ammo but the same rifle, the overall average of all the targets was 0.985".
The majority of the targets were shot using two different lots of Lapua, 18 of them with the same lot of CX and 17 with the same lot of M+. These averaged, .933" and .952", respectively. I also used another lot of M+ that gave similar results over nine targets. Nine targets were shot with other lots of CX, M+, and even X-Act were used, but these did not perform as well, with each averaging a little over 1.20".
While the lot of CX with which I shot the most targets was the most consistent overall in terms of group sizes, one of the M+ lots produced the smallest groups, including sub-.5 MOA. But it's important to note that it wasn't always very consistent. It was not uncommon for it to produce groups that were twice the size of its best groups. In other words, a box of ammo from this lot could have ten consecutive rounds that were very consistent, it could easily have rounds that open up the group.
Clearly not all lots of the same variety of ammo produce similar results. The two lots of CX I shot were very different with the rifle I was using. I didn't shoot enough targets with some of the lots I used to draw firm conclusions, but it's obvious that the name on the box is not what determines performance.
Below are some images of ten-shot groups that were good, but they weren't as regularly achieved as might be wished. The outside-to-outside measurements are shown. They were with the same lot of M+ but not on the same three-group target. Keep in mind, this same lot produced groups that could be twice the size of the smallest. The good lot of CX I used tended to give groups that were more consistent in size, but not necessarily the smallest.

The holy grail of ammo would, of course, be a lot that was consistent enough to produce similar groups with all rounds in a box. But that would be too much to hope for. Those kinds of lots are few and very far between and I doubt they ever get to our shores.
There are several ingredients for good results and they are a good rifle/barrel, good ammo (it's not the brand or variety), and good conditions, which means an absence of air movement -- either that or skillful use of wind flags. I think if you get a lot that can produce consistent ten shot groups at 100 that are under 1" (
i.e. most of them, not only a few), you will be doing well.