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P-fish: Technically that would be a bladed hand cannon (hand cannon referring to early firearms which were literally tubes you held in your hand or in the case of their eventual evolution into tubes mounted on the end of a wooden shaft so as to be better supported and held at a distance. What you've described however is technically to be considered a composite Pole axe and there area few rare examples of such an item dating back to 1510-ish London. Not bolt action of course but the general arrangement of barrel and axe/mace

That is to say its definitely doable.

Grenades: Make the bore big enough (like say 1" and muzzle loading and you could have it fire grape or explosive shells depending on what they loaded it with. Its lower tech than a bolt action but it doesn't take much to train peasants how to use a muzzle loader.

Crystal: touche

PG: not that i can recall, plenty of women fighters, lot of smaller, lighter weapons, and some nasty magic but not many with swords large enough to count I dont think...

I have Heart, but I hardly ever use it so I guess it doesn't really count sweatdrop

Dante's part of the mafi-*in the trunk*

Who needs gun or swords when you have fists!

Well Steampunk= heart so I understand.

Id advise against a metal shaft though, just use a more robust wood like Maple or Walnut if you want a solid shaft. Heavy, but much lighter than most metals ones. Though if it was completely hollow it may not be to heavy, but the price per unit would skyrocket and the shaft could bend in melee combat. The problem you'll encounter primarily is reloading with it on the end of a shaft. there really is no effect place to put a magazine on any sort thus complicating loading a tad.

Old style would be muzzle loading, with some sort of external ignition be it flintlock or matchlock (or wheel-lock if your that rich) the issue with a bolt action (besides being fairly modern) is that it means that the gun section needs to be sufficiently reinforced to handle a moving breach section as well as be of sufficient length to remove the cartridge and insert a new one which adds weight and length tot he mechanism or decreases barrel length. The other issue is that in a weapon on the end of a pole your accuracy is fairly nil at distance so there's really little reason for a rifled weapon versatility and simplicity would be your best friends in sucha design.

We all know Chen is a pansy, so I wouldn't put it passed him to say that.

Did Michael Jackson just moonwalk that piece of paper in half?

You know, I can't unsee that now since you brought up the resemblance.