Have you removed the stock ? It may not be original to the rifle ? Most I have seen are unnumbered or mismatched converted M96 beech stocks . Rare to see a matching HVA M38 stock . The disc may have been missing & a collector added one to fill the cutout ( not related to the actual bore ) . Also , look to see if the barrel is a replacement with a " Crown/letter " stamped on it & on the wrist of the stock .
I doubt you can judge a bore by a photo posted on the internet . Clean it well & use your own eyes to judge it > A #2 it not a bad bore !