How did you get the TAR21? I saw that it was to be found in one of the other zones. I never found anyone carrying one to pick it up.
Nice screenshots!
Good call on the markers, I didn't look into the HUD options.

You could go to that zone and complete the missions there.

Did you play the open beta ? it was on the new zone monteyuc,inside a BIG military compound, i splinter cell my way inside, just to get the gun.
As far as i know its only pickup, in the new zones enemies were using g36 (wich is only a reward via ubiclub for us),CZ 805 BREN A1 wich is only auto assault rifle, MPX wich is a OP smg ,seriously i was sniping fools from 140m with it,and i saw some with vector but i couldnt pick up, becouse of the body vanishing so couldnt find them.

Also as to HOW exacly, if you dont know, you can interrogate some LTs,they give you info on supply drops,raids,and skill points on the map.

Yeah, I played it. LOL
In the list of guns, it tells you in each gun description the area where you unlock it, but the zone was outside the playable area in the beta. I assume if you had it you picked it up off of a dead enemy like I did the M4, but I never found someone with the TAR21. I played for hours but still didn't finish all the possibilities in the beta area. I was just curious.

Then you didnt play the open beta, you played the closed one.
open beta happened 23 to 27,the gun was in the mountain area to the west. there were 2 .50 cal sniper rifles there as well, but only with acog, kinda stupid of them,to limit the scope in beta, enemy rifles had high magnification scopes

It was the open beta last weekend.



This map:



The region to unlock the TAR21 in the gun list was named on the map north of where we were able to play.
I did find a better sniper rifle, with scope. MSR? Something like that. A guy in a sniper tower near a helo pad had it.
Don't worry about it, it doesn't matter anyway. The game is out in a week and the beta is over.

It could (also?) be found to the west, which is the next area you go to.