That is pretty good at 500M with kirinkov since has a short barrel and infamous for accuracy.
You should try 300 yards with Kalashnikov. I am sure you can do well since you did well with Kirinkov.
I have shot down today 3''x6'' from 300 yards. Previously, I had it knocked down at 225.
As for body shot I think its no problem for me with iron sights up to 600-700.