There are serious challenges to making Gyrojet style rockets as accurate as rifle bullets. These haven't been solved at manufacturing scales, so snipers still use rifles after all these years.

However, there have been demonstrations of a guided 0.50 caliber bullet.

https://www.darpa.mil/news-events/2014-07-10

Is there reason to believe that gyrojets could be made practical? I was under the impression that there were fundamental flaws in the concept.

A small-arms-caliber recoilless rifle could work really well on a drone, though.

Gyrojets never took off because of how expensive they are to produce compared to conventional ammo. ($10 vs $0.50) Their only advantages are gun size and recoil.

Micro drone guns might actually be the one use case for gyrojets, because recoil and barrel weight are the most serious issues.

I thought the major issue was that they were extremely vulnerable to being blown off course during the slow-moving launch phase. Basically, that even a mild crosswind would send it irretrievably askew.

I assumed that the price issue could in theory be solved by mass production economies of scale, if the other issues could be sorted out.