My M44's shoot better with bayonet out. That does not mean that is how they were intended. I believe the Soviets issued its soldiers an 'accurate enough' rifle and told them to do thier part. And these short rifles are pretty good shooters in my opinion. Hot surplus ammo does give a pretty good kick...My understanding is that this isn’t quite correct, but do correct me if I’m mistaken.
I tried looking for original sources (or at least translations thereof) for this, but most results for this question are just other forums... and unfortunately there is quite a bit of forum lore out there that is plain untrue (for example that CZ-52’s are “stronger” in construction than TT’s).
According to Max Popenker (who is about as authoritative a source on Russian/Soviet small arms as exists), the intention that the rifle be fired with bayonet affixed applies to most patterns of Mosin up until the M38. This suggests by the 1944 pattern (ie M44) this was no longer the case. I’m aware that the M38 doesn’t have the option of a bayonet, but the way Popenker’s article reads, this ceased to be standard practice for every pattern designed from 1938 onwards.