Well, you could class the M82A1 (Barret .50 cal) as a semi-AT weapon, as it can take down lightly armoured vehicles.
A sniper who selectively targets a tank's sensor equipment (ond assorted other vunerable bits) can disable even an Abrams, so a standard SWS can be used in to do some damage to a tank. I don't think that this is viable in OFP at this point though.
I think that the best idea would be to take one of the Barret M82A1 addons out there (or make a new one) and make it a secondary weapon, not a primary. This would allow a sniper to have some anti-vehicle capability, while adding the ability to engage at extreme range.
An interesting effect of this would be the ability to take an assault rifle, and
a sniper rifle, like Marsuitor suggested. This isn't quite as cheesy as it sounds, as the M82 is not really useful against infantry except at extreme range, when you can't hit with a normal rifle, due to it's low rate of fire, and massive recoil.
[Off Topic...]On snipers being Special Forces:
Generally a sniper in a normal infantry unit is called a Designated Marksman. These snipers don't use as many unconventional warfare tactics as those snipers who operate in smaller groups. Any sniper operating in a small group (e.g. Sniper/Spotter) is going to have to use more UW than one backed up by an infantry squad.
MEU's are generally Special Operations Capable, which means that they are just as much a part of the "SpecOps" community as the SEALs etc...Marine forces are labelled SOC and not Special Forces, due to the fact that SOCOM doesn't have control of them.
[Note: The status of Force Recon as Special Forces may become official if the Marines contribute to SOCOM.]
[And this next bit is nice
Shit: Through the eyes of the Military
*An Army grunt stands in the rain with a 35 pound pack on his back, 15 lb. weapon in hand, after having marched 12 miles, and says, "This is shit!"
*An Army Airborne Ranger stands in the rain with a 45 lb. pack on his back, weapon in hand, after having jumped from an airplane and marched 18 miles, and says with a smile, "This is good shit!"
*A Navy SEAL lies in the mud, 55 LB pack on his back, weapon in hand, after swimming 10 miles to shore, crawling through a swamp and marching 25 miles at night past the enemy positions, says with a grin, "This really is great shit."
*A Marine Scout/Sniper, up to his nose in the stinking, bug-infested mud of a swamp with a 65 LB pack on his back and a weapon in both hands after jumping from an aircraft at high altitude, into the ocean, swimming 12 miles to the shore, killing several alligators to enter the swamp, then stalking 30 miles through the brush to an FFP, says, "I love this shit."
*The Air Force NCO sits in an easy chair in an air conditioned, carpeted office and says, "My e-mail's out? What kind of shit is this?"
-> www.marinescoutsniper.comAnd always remember: There is a sign at the USMC sniper school that reads "The average rounds expended per kill with the M16 in Vietnam was 50,000. Snipers averaged 1.3 rounds. The cost difference was $2300 v. 27 cents."
:wave: Liquid_Silence Out...