I ws waiting for this article to hit here since I got it in an SA email yesterday.
There's a big difference between a DMR (Designated Marksmanship Rifle) and simply attaching a red dot optic on a short-barreled rifle of any type and calling it a DMR.
Definition: A designated marksman rifle (DMR) is a scoped high-precision rifle used by infantrymen in the designated marksman (DM) role. It generally fills the engagement range gap between a service rifle and a dedicated sniper rifle, at around 300–600 meters (330–660 yds).
Can a SOCOMM and Scout Squad fling a round that far. Sure. But there's a big difference between what's considered a scoped high-precision rifle and a standard rifle with a red dot on it.
As HG said it depends on the size of the target and the red dot itself. The target at 500 yds. looks like its the size of a small car. As KF says it also depends on the visual acuity of the shooter. In both cases trying to pick out a man-sized target and place a precise shot is problematic, other than flinging rds out that far to keep heads down.
Also, a lot of folks think they're great shots when they can hit a steel target the size of a car or barn door at extended ranges, when in reality competition shooters & mil snipers are accomplishing far far better.
Also, I don't think SA came up with, and marketed the Squad Scout as a CQB variant but as a more portable version of the standard. The SOCOMM version is a different matter.
The article is what it is, an experiment on a known range at a large target, for shits & giggles. Put a real scope on for more precise shooting makes the Scout Squad (I have one) more versatile for longer ranges. IMO the SOCOMM is best used for shorter-ranged purposes, but it's never appealed to me.
My .02