In the 1950's and 1960's, the United States had lots of low-yield nuclear stuff. Artillery and bombs, a short-range recoilless rifle; things colloquially known as 'tactical nukes'.

Then nuclear weaponry below a certain yield was banned to lower the risk of nukes being employed in warfare. Russia was a signatory to this ban. However, while looking this up I came across a lot of news stories from May 2019 suggesting Russia may be carrying out banned nuclear testing with low-yield weapons. So that's not good.

But like people said, the artillery piece here is going to be the recipient of a lot of counter-battery fire if the Russian employ this thing against any professional military.