Base/critical damage -
Sniper Rifle - 42 / 42
Trail Carbine - 45 / 45 (can be increased even further by 25% with the Cowboy perk)
Hunting Rifle - 45 /45
Not much difference, though the Trail/Hunting are actually slightly higher.
Spread -
Sniper Rifle - 0.02
Trail Carbine - 0.03
Hunting Rifle - 0.035
Sniper clearly wins it, which is good for longer distances. But for 99% of your sniping, how much difference does 0.01 really make?
Critical Multiplier
All three are the same - x1
Scope -
Sniper Rifle - Long range
Trail Carbine - Mid range
Hunting Rifle - Long range
Trail carbine clearly comes off second best here. But even at mid range, and with a high sneak skill, you can probably get close enough to destroy your target due to the Trail's much improved damage (with Cowboy perk). Maybe.
Weapon HP -
Sniper Rifle - 80 (396 shots before breaking)
Trail Carbine - 500 (2494 shots before breaking)
Hunting Rifle - 300 (info not available, but can assume somewhere inbetween, say 1500, for example)
So, what the Sniper Rifle gains in accuracy, it clearly loses in weapon maintance, being one of the most fragile guns in the game. Either the 0.01 spread advantage that the Sniper has is so important that it overrides all other disadvantages or there isn't much advantage in maintaining it. Of course, the Sniper can have a silencer mod, which is another big advantage over the others. But even considering the advantage of a silencer, it would then be difficult to justify the existence of the Gobi Campaign Rifle, which is unmoddable.
If there is an easy answer to this, or I'm overlooking something obvious, please let me know.
