Since it keeps getting mentioned, I have to reiterate that unlocked L&K38 is really not something I would ever consider, even class locked. The model might be something used, but the archetype is detrimental to the game if it's unlocked.
Regular mechguns shine as a weapon because they translate all your base atp into 9 attacks (meaning that it's when you have shifta that they're powerful), whereas most other weapons only have 3 to 6 attacks. Stepping up from 9 attacks to 15 attacks is a large step up over that, and having that even as a class locked weapon still just makes it the de facto only weapon for that class because it so far outstrips the competition that there is no competition. You cannot have an unlocked lk38 at any atp value and still have any meaningful weapon balance/diversity/etc.
Those classes have access to Mille Faucille and Dual Birds, which while not as strong as Psycho Ravens, have an important factor that pr does not; they have significantly more range than pr, which is the most important stat for mechguns (hence why yas9k rules the mech department). Dual Birds have 120 range, while Mille is 100 with normal/hard and 130 with the autotarget special, about half again as far as Psycho Ravens standard 85 range (handgun range is 170). Hucaseal also really doesn't lack in damage, she is still the 4th highest atp char, but with the highest ata of any hunter she is one of the most consistent at her damage, and has better long range damage (at 30 shifta hucl with angel harp and sweetheart with no nearby males will actually still have better rifle range damage than a huct with asteron striker). Even though hucl lends itself better to being aggressive, she still does much better at all other ranges over hucast, and with that extra range she'll have already killed the monster by the time hucast is in range for PR. Racaseal is a char that can feel a bit weaker at times than racast, but much like before, she is the highest ata of all casts and significantly above racast in that regard (17ata if using kroe's). She is arguably the best character for doing content that uses a lot of hell or demon and freeze traps together, while still being able to use both cast and female gear like iron faust, gratia, kroes, sweetheart, etc.
We can't just make everything as strong as the strongest character (hucast) using the strongest weapons, characters have differences in their stats to emphasize differing abilities. At some point you have to ask when raw damage is "good enough" (most characters will 1-2 combo all enemies), and how to play to their other abilities to get the most out of them. There are things to buff up both of their damages like sweetheart, but because other stats are different they will not necessarily reach the exact same levels, you have to figure out where a 'comparably adequate' level is and reach that (for which 'how many attacks/combos to kill' is more useful than raw damage, where mechs almost never vary because of the overkill), and then figure out how to utilize their unique abilities to take them beyond that. Not every char will tackle solo games the same way, and in a team game they should all focus different aspects which some classes will do better than others.
I do feel racl needs a little more (though mille and macho blades did help her more than people give credit for), but an unlocked lk38 does not really mesh with racl well (and for hucl it'd be extraordinarily busted), it just tries to make racl into a ract that has none of their drawbacks and all of her strengths. I'd like to give her some more versatility and team supporting options that emphasize her range and teamplay capabilities, and while her damage could still use a nudge, only just a nudge and not an atom bomb in her arsenal.