The Mk12 uses a heavier 5.56 round than the standard M16s though, so it will likely have higher penetration. It actually helps back up the fact that heavier ammo goes further with greater accuracy lol, it's just like airsoft.
3 brick walls sounds about right for a 7.62, I'd have put that on the lower end of its penetration tbh, would've expected more.
Though I'm thinking 3 brick walls that are set up on a range with only 2 inches between them, whereas it probably means, through one house and half way through the next one...
Also, I've seen videos on YouTube of people hitting balloons at 900m with AR15s, whether or not they were modified or there was some dodgy camera work going on, I've no idea, but it can be done. So anything that's been altered to be better at that is going to be capable of it and I also know a guy who used to be an LSW gunner and an ex para who claims to have hit targets on a range at 900m with an LSW, so if they can equip them with the same ammo the Mk12 uses they'd probably be pretty effective.
The Sharpshooter is supposed to be for targets around the 800m mark though, but a site owner at Skirmish once casually implied whilst giving me a lift to the site that he'd dropped a guy at 600m with a standard L85, which are only supposed to be effective to about half that, so I guess the only limitation is the shooters ability lol.
That said, the longest range kill with a 7.62 is in the 1200m region, so 800m for the Sharpshooter sounds about right considering the record was done with a bolt action, getting that range accurately and consistently with a 5.56 would be exceptionally difficult/impossible. It was probably just the volume of fire that made it possible to hit targets at 900m, that or utterly perfect conditions.
h34r: 
