In ex-Yugoslavia countries using gr (usually without a dot) for grams used to be a fairly common thing. Last few decades as EU standardization takes place it's a lot rarer to see. Also in Croatia in everyday life people will far more often use decagrams (10g), shorten colloquially as 'deka', than grams - which leads to even more confusion because the SI abbreviation for decagrams is dag, not dg (which is decigram, 0.1g), and it's often mixed - even some primary school books had these typos.

Here in Italy is more common than any other form, I'd say

I've seen gr for grams. Not as common as just g, but it does get used every now and then.

yea, reads like "grains"

People do not know much about old cartridge powder measures though :D

"Grains" are still used for measuring out powder/chemicals (also arrows). If I saw "gr", I'd interpret that as grains rather than grammes as "g" is definitely grammes, so the extra "r" must signify something.

Air rifle bullets are typically specified in grains, for example