WHY CAN'T I KILL ANYONE WITH GUNS!?!? IT'S 100% CONDITION!!! - originally made by @jovial vale, polished by @prisma sorrel and @thorn kelp
Check which ammo type you're using.
— HP and Buckshot are usually used for mutants (but on occasion works well on lightly armored stalkers).
— AP works best against armored NPCs. Buckshot and HP might only stun those with higher armor and do minuscule damage at best.
— FMJ is somewhere in-between, when your foe is wearing light to medium amounts of armor it can work well for saving AP ammo.
Next, check your weapon details:
(See image)
The worse condition your parts are, the less effective your firearm is (more jamming), and the worse condition your barrel is, the less damage you'll do.
F.A.Q. ABOUT AMMO
Q: Is it better to use AP ammo against high tier armored Sinners?
A: Typically, YES, you'd want to use AP ammo against armored sinners, the same AP vs Armor rules apply to them as it does to other non-sin stalkers, but they (sin) will always be able to tank more bullets than normal stalkers.
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Q: For the player, does BR % work after BR Class is penetrated or if not penetrated? What is the difference between BR Class and BR %?
A: The short answer is that when dealing with the actor (player) BR Class is the armor’s maximum AP resistance, if the ammo can defeat & penetrate the armor BR % will reduce the amount of incoming damage you receive.
The complex answer is that when the incoming bullet doesn't penetrate your armor or helmet, damage reduction will be applied, damage reduction is calculated through this formula "damage reduction = ballistics resistance (aka BR %) * 0.2 + br class * 1.3" only if the bullet doesn't pen your armor.
This formula only applies to resistances coming directly from your helmet/armor and does not account for belt items/buffs. If the bullet does penetrate your armor/helmet then "damage reduction = ballistics resistance (aka BR %)" and you will start to bleed.
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Q: What happens with AP bullet that cannot penetrate?
A: If a bullet is not able to penetrate armor, it will start breaking (dealing damage) to said stalkers armor, once enough damage is done to a specific part of the stalker their armor will break, allowing you to do full damage to that part of the stalker. Additionally, when armor can defeat the AP of a bullet the stalker will still receive concussion damage. To simplify, think of concussion damage as blunt force against armor, it’s affected by bullet size, the larger the bullet, the more concussion damage received. Player armor can technically break, but not the same way NPC armor does, it's just simple armor degradation (condition loss), but otherwise you will still receive small amounts of damage from bullets regardless if your armor stopped the bullet.
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Q: What "breaks" armor better: HP or AP?
A: The only factor that plays into breaking armor is bullet AP. A distinction needs to be made here from AP rounds and the bullets AP, AP rounds will break armor much better than HP rounds, but because HP rounds still have an AP value, they will also break armor (albeit much slower) so use AP bullets to break armor.
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Q: Does AP penetration reduces when shooting at Sinners?
A: No, not at all, the AP penetration of bullets will still apply to sinners, however sinners will take much less damage due to their flat 65% damage reduction.