That LB, actually looks to be in decent shape.
Yes, it's dirty and dusty but that doesn't mean the rifle hasn't been taken care of properly.
It means that it may just have been in a fight and dropped in the dirt.
The rust on it may be from several things as it looks recent, rather than something that's been there for a long time.
The mag and bolt are missing as well. The stock is in surprisingly good condition as well.
I'm willing to bet that old girl was a prized possession and lovingly taken care of.
I'm willing to bet the rifle was rendered inoperable by the removal of the bolt and mag then thrown onto a pile, with a bunch of other captures.
Riflechair is correct, from a stable, position a 600 yard shot is relatively easy with open sights. After all is said and done, pinpoint accuracy isn't required. Any hit to a person, armored or not is going to hurt like hell and demoralize anyone in the immediate area.
At the very least, it will drive them to cover.
There is a lot to be said for "battle rifles" effectiveness, even in today's armies.
There is a good reason why so many M14s and FNFALs were shipped over there as equalizers.
Back in the early seventies, there was still some speculation amongst armies of the world to issue a couple of intermediate round capable rifles with each squad. Bolt actions, weren't ruled out.
The big thing was supply issues and decent ammunition consistency.
The intermediate round was most certainly going to be the 7.62x51 Nato but it was soon put to rest as a bad idea.
Funny thing though, a lot of M1 Garands and M14s managed to find their way into the jungles of Viet Nam with US forces.
The Marines, were issued M14s for quite awhile after the war started.
I'm not the least bit surprised to see that old war horse there. If the internals are decent and the user was reasonably trained in its use, it would be a fearsome opponent right out to and even beyond 1000yards.
There is no reason to believe the Afghanis aren't good marksmen. They have a long tradition of being accomplished warriors.
Many of them are born to it, just like many of us are born to military families as well as hunting/sport shooting families.
They've been trained by the Russians, Chinese, British and Pakistanis. More than likely even a few privateers as well.
That old LB, in the right hands, could easily be used as a force muliplier when applied properly.