Uh, no, you are looking at this wrong and your labels are off.

The AP already has 2 monster families that it does better against (fiend and undead), 2 that it does worse against (slime and gremlin) and 2 that it does intermediate against (beast and construct). The "intermediate" damage can be considered "normal" for all practical purposes, you just have to adjust the base damage up or down to what you think normal should be. If a normal gun does 100 damage against beasts/constructs and an AP does 105 against them, then the AP is better than the other gun, if it does 95, it is worse than the normal gun.

To repeat what I said in this thread

To put some numbers to this...

My understanding is that when a weapon is strong against a monster, it does 150% of the neutral damage amount, and when it is weak against a monster, it does only 25% of the damage.

When you have two non-normal damage types on a weapon, you get the following:

strong and neutral: 0.5*1.5+0.5*1 = 1.25 -> 125%
strong and weak: 0.5*1.5+0.5*0.25 = 0.875 -> 87.5%
neutral and weak: 0.5*1+0.5*0.25 = 0.675 -> 62.5%

the best case is 43% better than the middle case, while the middle case is 40% better than the worst. It doesn't make any difference if the middle case is "87.5%", or "100%" or "1%", it is the ratios that matter. The AP (and other weapons that do two kinds of non-normal damage) are much more evenly balanced between their best case and their worst case.

If a weapon does both normal damage and a non-normal damage type, the result is between a weapon that does pure normal, and one that does two non-normal damage types.

strong and normal: 0.5*1.5+0.5*1 = 1.25 -> 125%
neutral and normal: 0.5*1+0.5*1 = 1 -> 100%
weak and normal: 0.5*0.25+0.5*1 = -> 62.5%

The best case is 25% better than the middle case, while the middle case is 60% better than the worst case. Again, it doesn't matter if the middle case is "100%", or "87.5%" or "1%", it is the ratios that matter.

"Fixed?" I think weapon choice should be fixed. If we're trying to move around the "supereffectivenesses" of this game, then we're moving a lot more stuff around. If you don't like how the AP or any other weapon deals that damage, choose another weapon, please. No need to move around the nuts and bolts of the game. Maybe move this to Suggestions thread? And maybe say what NEEDS to be moved, like if it needs to be buffed or something? Because all I read was the exact things that need to happen in game. And Chris, I think OOO understands this game, but players do not, therefore are complaining against what has been working since the game started. "[players] clearly have some problems understanding their own game lol." [PS sorry Chris but this is the threads. You're another player posting in them if you think this is offensive]

Enemies in this game resist damage way more than they are weak against. This means that using the AP against constructs and beasts will not give neutral damage, since the bonus damage they get will be less than how much less damage is from the resistances, it's just how the game works. They should keep it this way.
And you can't base what the gun is good against by what color numbers show up when hitting enemies, it's isn't very reliable. The gun does do better damage against fiends than what you may think from what you see.
You also have to realize that the AP and other Antigua lines are not going to be the most damaging guns since they aren't pure-typed. The gun has the biggest clip size (counting the autoguns as a 2 shot clip), fast firing rate, quick bullets, and has longer range than most of the other guns in the game. On top of that you are fully mobile while firing unless you're reloading.
If you're complaining about the gun and how it needs to be fixed because of damage, you should probably take a look at the good side of the gun first before asking them to fix it. If you really want them to buff the AP, they need to buff all of the other guns as well.

the problem here is that monster's weaknesses are not so pronunciated as resistances are... thats why i always said its the worst gun in spiral knights
(but very useful in FSC)

The only real fix it needs is its buggy hitbox. If you're spamming your Antigua-line gun you'll sometimes find that if you don't hit it right on (and in some cases, even when you do) it doesn't hit at all. It's like it's stopping close to the enemy, but not close enough for the tiny splash to actually hit and harm the enemy. It's very annoying to fire a full clip of six bullets, only to have three to four of them actually hitting. I have this happen a lot when hitting enemies a bit to the side, but not far enough to actually miss the mob entirely, yet, the hit doesn't count.

and you could try being nicer to someone who's trying to help.

i dont actually have numbers or any proof of this, but try getting into a fiend arena with a flourish (that's where you can find fiend and construct together) and you'll see what im talking about.

and BTW my silversix always deals bonus dmg against fiend.

Slow down there big boy.. AP does the exact same numerical damage to fiends and undead, not sure where you got the idea that it doesn't. If you're talking about the colors, they're glitchy: the damage numbers are correct. As for the other classes, damage penalties (25%) far outweigh bonuses (150%), so the AP is still going to be doing less than neutral damage to beasts and constructs and even less to slimes and gremlins.

First problem is that you're testing this gun in the third stratum. Test it in the 5th or 6th stratum (Tier 3) because it's a Tier 3 weapon.

This thread is very disappointing, as there was a stratum right before FSC (and actually, after the rotation, still is now) that has the fiend levels which are also populated by Spookats.

Also just tried it now. Depth 19, fully leveled Argent Peacemaker with no damage bonus to both Fiends and Undead:
Damage to Normal Devilite: 53
Damage to Normal Spookat: 53

Again, very disappointed that this was easily testable, yet debating without easily comparable numbers.