I've got an excellent very lightly used L39A1. All original right down to the .303 mag used as a loading platform. Has a twin zero micrometer sight and larger matchmaker fore-site. I use later anschutz clear acrylic "slim line" sight inserts. I'll be taking it out this Sunday and shoot it at 600 with the full bore guys (as I normally shoot it in service rifle). Might swap with somebody a send a few rounds down to get a comparison.
All the things are there for an accurate rifle....heavy long hammer forged freely floating barrel. Action hung trigger with crisp two stage, good sights. But we're talking about a 1970's target rifle based on a 1930's receiver, with 1940's sights. Not a lot has changed in the grand scheme of things technically...but you'd want to think they're making more accurate target rifles in the 40 years since.
All I know is that in the prone position I can group it pretty well, but you'd need a rest or sled to compare apples for 7.62 apples. But it's not going to win a Queens Prize.