I have a player who likes the Siskan Musket, his only question is the pen as it's a primitive weapon. Is it possible to get mono bullets for it? Also what about monoing arrows? Darts? Bolas?

I know it's possible to mono literally every kind of melee weapon, represented in different ways (liquid core in a staff, spikes on brass knuckles, the only exception being shields)

So my question as a GM is, why not mono ammo? What should this cost?

My opinion is use Manstopper ammo cost and just apply the mono effect to the weapon.

If he eventually wants to get lathe bullets, how much would that cost? 2500 per 30 rounds for regular bullets? 2500 for 20 high cal? Etc.

Sorry for the bad grammar.

I allow acquiring mono (and lathe-wrought) arrows, darts, crossbow bolts, javelins, etc. as there's little difference between putting a better quality edge on a better quality knife and putting a better quality edge on a better quality arrowhead. Generally speaking, primitive Rending is allowed, but anything else is case-by-case, and backed by the player coming up with the justification of how it works.

Lathe-bullets are the Hyper-Dense Penetrators, aka Body-Blowers. And they are weapon-restricted.

However ... I would not go for mono-upgrading musket balls - as in that case, it's both a combination of the inferiority of the round itself, the powder used to propel it, and the bore pressures the weapon can sustain.

And, frankly, the real value of a Siskan Musket is in the thematic nature of it - not its practicality as a weapon. It's a black-powder musket that uses a human femur as its stock - usually either the bone of an ancestor or an enemy you killed. It is not practical or viable as a weapon anywhere other than a black-powder-age world. And it shouldn't be.

However, I could maybe see allowing one to imbue its shots with the Holy quality or otherwise have bonuses against daemons and psychic defenses, if the bone came from a Saint, or sufficiently Faithful personage and the weapon was of good or best quality - such a weapon would be special, and not something you would be able to easily acquire.

Okay. I'm thinking maybe allowing him to put the grav-accelerater on it that forces the projectiles out faster,or statting percussion caps up as an upgrade. It's still not going to be an efficient weapon by any means, as he's put thousands of thrones into the weapon at this point, but having to keep it primitive is overtly limiting to me. Maybe both. After all, it's a best craftsmanship weapon, and even with rapid reload and a tacrig to aid in reloads it takes 1 full and 1 half action to reload it, with a clip of one. Keeping in mind that the character is an ordo xenos inquisitor, giving it the sanctified or holy qualities don't seem to make much sense.

So as I see it he can have the gun reworked as a percussion cap weapon for 1000 thrones, given the grab accelerater for the usual amount+500 and his bullets cost the same amount as manstoppers. This would all be done to decrease the reload to half, increase pen by 1/2 and remove the primitive quality. He has reasonable BS to make called shots as he's starting as an ascension level inquisitor.

Thoughts? Suggestions?

There are physical limitations on what you can do with black powder and an iron barrel.

Is this supposed to be upgrading an already existing weapon or a custom-commission?

If it's an already existing weapon ... frankly, I'd actually say go swipe and tweak the Legacy Weapon rules from Black Crusade's Tome of Blood, if you've got access to it.

Plus, an upgrade like the grav accelerator is, in my opinion, the sort of thing that should be included as part of the weapon's initial creation, not an aftermarket add-on.

Also, while a percussion cap could speed reloading somewhat, it likely wouldn't be that significant, assuming a good design with the touch-hole and the pan ... which it probably actually doesn't have. The biggest timesuck in the loading cycle would be the fact that it's a muzzle-loader, and uses loose powder instead of cartridges. It would likely be possible to commission a breach-loading design, but, modifying an existing weapon could be problemmatic - not necessarily for technical reasons, but for techno-theological ones. Switching to cartridges from loose power would be something that using a percussion cap would allow you to do, but base reload for a cartridge breach loader with external percussion caps, rather than caps in the cartridge (in which case you've gone and upgraded all the way to a primitive stub gun), would likely be 2-3 full rounds (the nominal sustained unit fire rate IRL is 1 shot every 12 seconds or so for a very well trained and practiced unit, IIRC)

Actually, if it's a custom-job, for a freshly started game, I'd still probably swipe and modify the Legacy Weapon rules if the weapon is as big to the character as you seem to be saying, and it's in the backstory.

Now that I think about it, the only thing really in need of significant modification to adapt the Legacy Weapon rules would be Infamy and Infamy Bonus ... Infamy is used to upgrade one's Legacy Weapon, and Infamy Bonus adds damage/penetration, and is sometimes used for other effects as well. BC Core's suggested starting Infamy for a DH character translated to BC is 1d5+19 ... for an Inquisitor, even a brand new one, or any Ascension character, really, I'd probably add 2-3d10 more or just double it.

Hmm. I suppose that could make sense and work. Thanks!

I could see mono bullets as fragmentary bullets that exploes upon impact and each bullets is a lot a razor-sharps edges, but on the other hand, tearing would represent this way better.

Have fun, if there can be a good reason for it to be this way, do it. But hey, I think going instead to legacy weapon with WP bonus instead of Infamy bonus would be a nice fit; this is a weapon that was held by a chaman for hundreds of years in a tribe and now, the character has got the right to use it and stars shines on him when he uses it, giving him big bonuses that will make the gun way better, without it being actually something else.