On wiki they list Polish special forces as the only .gov user of the ACR.

Anyone know of other .gov use?  Even police?

Curious as well, pretty sure it’s just the poles though

I would be surprised if not a single LE agency somewhere didnt pick them up.

GROM doesn't use the Acr.  They received some test samples of the early model and then stole the design.  That was when the MSBS was born.

There's not a long list of people that rock the Bushmaster or even the Remington Acr.  Mostly because it's not an AR15 patterned rifle.

They did solicit it for the Army IC trials in 2012 or so.

Department of Homeland Security wanted 6k of the PDW's but that deal never happened and it went by the wayside.
The Border Patrol was testing/evaluating them as well.
Remington has sent Acr's out to police departments but I'm not sure which models they sent.
There were probably a few other agencies that received test samples but those are the ones off the top of my head.

Not necessarily GROM.

http://soldiersystems.net/2012/04/18/polish-use-of-acr-in-afghanistan/

That came from both Remington and one of my buddies that is an acr guy. He works for border patrol in Texas and shoots competitively.

I don’t know which Acr they were evaluating but it was a remdef.

Also there is no spec for the remdef Acr. They are built as requested.  The pdw was about the only real Remington Acr that was a final model.

Funny enough the pdw is insanely rare compared to the other models too

Fact that Remington Defense doesn't list the ACR anymore should tell you about its future as well...