I put on a Mosin shoot where we shoot half shilouettes (20” wide) at 2,3 and 600 yds. Prone, unsupported with a sling for support only. Good shooters hit at 600. Most rifles can outshoot 99pct of shooters.
That sounds like a fun shoot.
A Mosin Nagant is more difficult to shoot accurately than a modern high quality rifle and they have other deficits also. But that is an apples to oranges comparison.
I have a restored 1941 Cadillac and a 1942 Cadillac that I am working on. They are amazing cars and I appreciate them greatly. They were arguably the finest automobiles in their day. Are they as easy to drive and maintain as a late model car? Obviously not, but they are certainly not junk. And their ride over the kind of crappy roads they had back in the 40s is amazing.