Had a pal with a HMR who cleaned it and then moaned about its accuracy, this was several years back!
So I told him to clean it and when he was happy with his cleaning give it to me...….this was the result of me cleaning his already clean barrel, I took the pics to show him!
Top, right to left, bottom left to right, with a scrub between each patch! The HMR is a tiny little calibre that needs careful attention and thorough cleaning.
I am not suggesting for a minute you are not cleaning it properly, there could well be other issues with the ammo, crown, moderator etc, but it does