I am sceptical. The rotor head of a Mi-24 is a real beast of a thing, they make the things out of titanium and i'd be sceptical that even a perfect shot from an anti-material rifle no mater aa normal .303 round would be enough to do more damage to it than it would take to prevent it at least limping back to base. The main rotor blades themselves are also real thick things, they're beyond the capacity of a rifle calibre weapon to do serious damage to and in any case doing damage to enough of the three that it couldn't limp home with a bolt action no mater you skill seems unlikely to me.

The tail rotor is more vulnerable but even if you did catastrophic damage with a rifle to one which would seem to be difficult under most circumstances with regular rifle calibre bolt action, there is a strong chance that the aircraft would be able to make an emergency landing intact due to the Mi-24's design with the little wings on the side that help to prevent it spinning out of control. Its extremely difficult to turn the aircraft like this but you can land safely for the most part in a Hind.

But that's not the kind of shot that the calibre of snipers most insurgencies can produce will be able to pull off with any consistency under most circumstances. Its a fairly small target and the Hind has trouble hovering perfectly stationary even when it wants to so you'd be unlikely to have a stationary target at any given point. Given there's no physical way to aim at an individual rotor blade as the three spin its the kind of target you're much more likely to hit with volume of fire as opposed to individual round accuracy.

Even if this ever did occur it wasn't the standard tool for the job. The weapons the Mujahedeen used most often where heavy machine guns like the DShK and ZPU family, light autocannons like the ZU-23-2, unguided shoulder launched munitions like the RPG-7 and MANPADs like the Stinger. I should also mention that its as much the circumstances that afforded the opportunity for a kill as the weapon to.

For heavy machineguns particular the 12.7x108 ones like the DSuK the Hind was pretty resistant to them most places so you needed a relatively short range such as a weapons position concealed on the side of a mountain being able to engage a passing aircraft that's flying low over a valley or one of the ideal circumstances to engage a Hind and most helicopters when they're taking off or touching down. Because with the infantry payload the hind in the transport role was even more of a bitch to fly and the fact that under all circumstances the moment of being relatively stationary at low altitude means that if you've got a concealed position within 1000, 2000m of the target ad you've got a half decent chance at it. The ZPU family would be able to do the job more reliably as long as you could find the chance to engage the aircraft at relatively short range. They came in different mounts with the ZPU-1, 2 and 4 having a single double and quad barrel respectively. There's a certain trade off there in portability and conceal ability and necessarily quantity of ammo you've got to transport with the larger set up also requiring a larger carriage which was harder to transport on foot over rough ground. But with more barrels comes a greater volume of fire and combined with the larger 14.5x114mm round you've got an increased chance of successfully hitting on the parts of the aircraft that might be vulnerable to the round at shorter ranges such as the turbine intakes, the windscreen and the tail rotor. And the large 14.5 round has an increased chance of being able to penetrate and do serious damage to this kind of thing.

With the ZU-23-2 you've got as the name suggests a pair of 23mm autocannons here. Again, larger gun lower portability and concealability but if you've got them at short ranges you're getting to the size where you're beginning to get the punch required to potentially have a semi-decent chance of punching through the fusillade with the right ammo. The effective range of the larger round against an aircraft the size of the hind is increased compared to the .50, .57 cal guns also helps to increase the number of opportunities you might have to reach out and touch the aircraft and have a half decent chance of doing damage.

Weapons like the RPG-7 where also used. On the one hand they're very portable and could potentially penetrate any part of the aircraft. But they also require a short range to be effective. You can't shoot one past about 900m at all and really hitting anything past a couple of hundred meters is pretty difficult. Particularly difficult if the aircraft is moving fast and while the Hind isn't the most manoeuvrable of aircraft for its day it wasn't all that slow. Plus of course if the pilot saw the incoming projectile the chance of a hit goes down further as they can try pull an evasive manoeuvre.

Then you have MANPADs, Man Portable Air Defence, guided missiles often fired from the shoulder with the Stinger being particularly common. The Americans sent these over to support the Mujahideen. They did have some major advantages over other weapons systems. Exactly how many Soviet aircraft where destroyed in Afghanistan in general is debated and specifically how many where taken out by stingers is in particular. They did offer the advantage of being useable from a longer range, being man portable easily and the weapon being small enough it wasn't so hard to produce a concealed position for the team. Their heat seeking ability significantly reduced the chances that the pilots would be able to avoid the missiles once fired to. They didn't necessarily guarantee a kill though as even a solid hit wouldn't necessarily actually shoot the aircraft down as opposed to force it to return to base. Additionally while it came at the cost of some performance and/or weapons systems things like flair launchers, chaff launchers and hot brick infra red jammers were variously used to reduce the ability of the missiles to get a lock. The other thing was that the things were so valuable on the market that some mujahideen leaders for one reason or another figured they were better off taking Stingers off the Americans and selling them.

The other poster is right to be skeptical. We have publicly-available and fairly complete records of every aircraft loss in the war, and while the exact weapon is not listed for every shootdown, it's listed for most. (These records have been condensed into a pretty accessible form at http://www.skywar.ru/afghan6.html). Of the Hinds lost to small arms fire, the majority are from DShk heavy machine guns. There are a number of unspecified "lost to small arms fire" entries as well, but any lost specifically to aimed gunfire hitting the rotor hub would likely have been noted - assuming the airframe was in good enough shape on landing to analyze, of course. So it's certainly possible that one or two were lost this way and it simply wasn't recorded, or the Soviets weren't able to determine this from the wreckage. The Lee-Enfield was certainly in combat use by the Afghans, it's remarked on in the official Soviet command staff report on the war so there's a whiff of possibility if not plausibility. However, between the difficulty of landing such a shot on any of the exposed vulnerable surfaces and the relatively small portion of Hinds lost to unspecified small arms fire, I would rate the likelihood as low. It's somewhat more conceivable that one or two less-well-armored Mi-8s were lost this way; there are a few that are listed as crashing when the pilot was killed by small arms fire, and massed bolt-action rifle fire against an unarmored helicopter could have an effect. But the primary killer of Hinds appears to have been DShKs and massed automatic gunfire.