I was researching the metrics comparing the sniper bolt and the bolt carbine to determine whether my desire to buff the sniper is truly necessary or just a personal impression. Please feel free to correct me in any way or contribute to the discussion.

I will present a damage output comparison here, without considering skill-based or headshot damage buffs. That is a separate discussion regarding the difficulty of consistently landing headshots, especially for console players in high-difficulty settings. 

My goal is simply to demonstrate that the bolt sniper should, by all means, be stronger than the average bolt carbine. In my opinion, despite having roughly three times the damage output, it is still not necessarily better.

Please note that I am using the standard version of both weapons and the average settings for the Majoris health indicator (123.2 HP)

Bolt Sniper Rifle :

breakdown : 

13 shoots because with 12 hits you'd hit 120 DMG, and since you can't fire half a bullet, you'd need another one to hit the full HP target (123.2)

1 Majoris killed with total ammo because after killing the first one (13 shoots), you would have 5 shoots left, dealing 50 DMG, not enough to kill another majoris.

Bolt Carbine:

Even though the bolt carbine has significantly less power than the sniper bolt, it is more efficient in combat, as it allows you to take down three times more Majoris.

As I mentioned above, I am not considering headshot multipliers, skill buffs, or similar factors. My main point is that, in my opinion, the bolt rifle should either have higher damage output (regardless of headshot damage) or more ammo. Otherwise, in practical terms, it won't truly feel like a high-powered sniper rifle but rather a very long semi-auto bolt carbine with low ammo and a slow rate of fire.

With every weapon and class perk the Sniper can get 185% damage to a headshot with the first shot out of stealth yet that isn't even a 1 shot kill on a Tyranid Warrior on Ruthless difficulty. I'd say that makes it quite clear that if you can't get the kill even with using your ability then you weapon clearly needs a buff.