taschoene said:

Yeah, I'm curious too (I can't see it either). That claim does run counter to most other sources I can find. You can definitely find tons of patents for improvements on BB technology to limit the dispersion problem. But AFAIK, not many claim they can do better than a basic boat-tail.

Well its not unreasonable that the problem of ignition and even burn was solved. I would argue it could have been done allready in the '70. But most likely the cost per shot would have been prohibitive.
Basically a BB gas generator is a slow burn rocket or a fast burn tracer. Depending upon details and approch. The fast burn tracer is most likely cheap and simple but will produce the problems with ignition and even burn. Just as tracers do.
A rocket on the other hand can be controlled very precisely. This was allready the case in the '70. But its more complex and more expensive.

My guess is they successfully managed to combine the advatanges of both approches into one to get the advantages of both.

In addition a lot of problems with dispersion, deviation, uneven burn, loose or tigh fitting are not due to physics or technical problems. For mass products like munitions if often the manufacturing and quality controll. If you have these under controll and establish the proper processes and methods all of a sudden things that seemed not to work or problematic become nice and simple. But it takes the will to spend money and invest in production and QM. Which often is not there. Once R&D is done ofte the assumption is that if the design is handed over to production the mass produced item will automatically perform exactly and be build exactly to the same specs as the manually build prototypes. Which is a very, very bad mistake. The Swedes have traditionally very good process and quality management. They also have a high class industry that is working to very high standards with modern methods. To me it makes perfect sense that they managed to pull it off if they really have put their mind to it and invested resources.

mpopenker said:  "US could make problems out of thin air even when presented with a complete and well-established design, just google up T-24 machine gun, or a more recent Century Arms AK-47 ;)"

I've worked around the U.S. aerospace industry for the past 40+ years and find your comment to be a massive understatement.

RRBud said:

I've worked around the U.S. aerospace industry for the past 40+ years and find your comment to be a massive understatement.

I have similar experiences.
Most likely its true for every point in time trough all of human history regardless of place and culture. As soon as bureaucrats and politicians get involved things often go south.
The difference is in how transparent such happenings are and how they are comunicated.

There is no kill like overkill!

I heard a machinegun owner refer to this as "how to turn money into noise and smoke" (and in this case, fire).  Just watching that video caused a significant pain in my wallet!

LOL.  Yeah, it's certainly expensive.  However, I think most machine gun hobbyists are wealthy enough that they don't care about the $$$ spent.