Achieving precision rifle reloads is easy only once you've achieved precision rifle reloads.

Very useful as an accuracy indicator, but not definitive by itself.

Shooting groups for the sake for shooting groups is, for me, ammunition better spent shooting targets at range in the wind.

Shooting groups for group size is meaningful in the context of load development, when you incrementally adjust the seating depth to change the group size.

You will quickly figure out that for group sizes based on seating depth changes, you need to first be able to shoot consistently good groups as well as load precision ammunition. Parallel tracks that intersect. You cannot identify a good group from a load if you cannot shoot a good group. Before you can do this test, you have to be able to reload precision ammo. Parallel tracks, intersecting.

To shrink group sizes at long range needs a low ES load to work from, and adjustments to seating depth and / or neck tension.

This factor, combined with small group sizes at long range, is what defines accurate reloads.

Be aware that low ES is not an end goal by itself : the end goal is minimal shot dispersion on target at the required distance. The lowest ES does not always give the lowest shot dispersion on target. You may find a higher ES load gives a lower dispersion than one with a lower ES.

Low ES is a product of powder type, charge weight, bullet, brass quality, neck tension and primer selection. You should test at least a few combinations, giving yourself a better chance of arriving at a low ES. Start off with Lapua or Norma brass. You can then eliminate brass quality as a variable and save a lot of time and effort.

No honest pro shooter will claim low ES is everything. The ones that honestly want to help you improve will tell you to look on the target, not on the chrony.

Precise shooting requires precise ammunition.

Producing precise ammunition requires load development. It is straight forward to get into the load development ballpark, with a bit more work to find the goalposts.

Component selection is a critical aspect of load development, the importance of which cannot be overstated. Like trying to breathe without oxygen. Variation in components will cancel accuracy. It takes trial and error to finalise component selection, which is a necessary phase to progress through towards achieving accurate reloads. Only through trial and error will you determine that the difference between an accurate and inaccurate load is just a component change. The sheer number of component possibilities is daunting. A very underrated and very effective way to simplify your initial component selection process is to use what someone who you consider to be successful is using.

Monolithic bullets have different requirements that need to be considered for accuracy. I find that the bullet jump and velocity affects accuracy more in the case of monolithics. In my rifles, the monolithics prefer a longer run to the rifling, and a lower than published velocity.

Some people refuse to spend money on quality components, and try to make precision reloads from cheap products. One day, the world will hear of one who succeeded. So far, millions have not.

The precise measurement of components, component quantities and assembled dimensions do not result in accurate reloads by virtue of themselves. The definitive metrics for accurate reloads are ES and group size. Group size will show that the bullet is delivered consistently from the platform. ES will show when the vertical dispersion is minimised at range.

A low ES on it's own will not always give a small group size, and a small group size is not always from a low ES, and neither on their own translates to downrange accuracy. Accuracy past the zero range depends entirely on both. The seating depth will have to be incrementally changed to arrive at the intersection of low ES and small group size. You'll never be able to identify that point if you cannot hold a consistent zero with the rifle, or are not able to reload precision ammunition. Parallel tracks that intersect.