that cant be a crack... ive seen cracks.years ago a friends father loaded a 38spl with .357s and blew his new gun apart... i see now your issue was clarified
Every firearm shoots (and feels) different - shoot it a bunch, get used to it, get a feel for it. I hated the S&W model 64 I was issued way back in 1983 (little gun, fixed sights), but darned if that thing doesn't shoot well now.
i was gonna post and say that if you had a hot round that would crack a gun it would crack or explode the cyclinder way before it would crack the frame. i had a rossie .44spl and it looks just like that nuthing out of the ordinary . glad the gunsmith cleared it up for you.