Thank you, I tried a long time for this and gave up. I then came back to this with your help and finally got it done.

Sorry. This is in regards to #4.

I'm not sure if coordinates differ between using metric or imperial. I used imperial and coordinates are: 7135, 7470 from center of circle. Target is SE.

#10 glitched for me. It was down by default.
You can still hit it when it’s sideways, just a harder shot is all. It will flip “up” into the bridge after so shoot it again to knock it down so you don’t launch your ATV off the bridge like I did.

Supreme guide, even logged in to give a thumbs up

i hit all 15 says mission complete. Although it does say something about challenge targets no idea. But the point is the gun did not unlock for me.

@Slysi I'm happy that my guide helped you

Steam Achievement - Hitting the Mark
Complete one of Carolina's Challenge Targets
Unlocked 27 Mar @ 1:22am

Steam Achievement - Carolina's Greatest Hits, Shot-For-Shot
Complete all of Carolina's Challenge Targets
Unlocked 27 Mar @ 2:55am

Rifle Unlocked - RangeMaster 338 Championship
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15 Targets - 1 hour 33 minutes (I didn't have the map fully explored before starting)

Apexview 7x42 Binoculars
Virant .22LR Klasika - w/Hyperion
Zarza-15 .223 Midnight - w/Hyperion
Zarza-10 .308 Stalker - w/Argus
Saber 4x4 - Crimson
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@callmeBG - Thanks very nice guide

Thank you very very much

You have to hit all 15 targets only