Weapon proficiency on crafted weapons question.

[SwitcherOccifer]

If my Artificer crafts his own crossbow, does that mean he is or has to be proficient with it? He's already proficient with the light crossbow, but the hand Xbow is exotic.
Clarification: My Artificer wants to "upgrade" his personal weapons in a mundane fashion. Adding a stock for stability and a scope for better aiming. Adding a stock would basically make it a light xbow, and adding a "pump" would make it repeating, so on... The repeating magazine for the bolts would hold all the magic enhancements, not the bow.
The xbow body will have an eternal greater magic weapon wand in it to cover the +1-+5, and the magazine will have a total of +5 on it for each magazine. The magazines are wonderous items and can only carry one enhancement at a time, determined at its creation. If the enhancement is less than +5, than the magazine will carry additional ammo. Ex. The splitting enhancement is a +3. A +1 to ammo adds 5 bolts to the storage capacity. A splitting bolt magazine can carry up to 15 splitting bolts.
TL:DR- does the personal restriction on a crafted item imply weapon proficiency?
Thanks!

[Kayblis]

Crafting doesn't mean anything to Proficiency. They're completely divorced mechanics. If you craft a weapon you're not proficient with, you still take the -4 proficiency penalty.

What you're trying to do is basically another question: "If I put enough alterations on a weapon, does it become another weapon?" And the answer to it is completely GM-dependant. When you make a weapon, you use raw materials that cost around 1/3 the weapon's cost, like wood and metal. If you want to use a finished product as "material" for a completely different weapon, you can't just say it's the same item. But, if you are just stacking alterations and paying for each one, your GM might let it just be an enhanced version of the Light Crossbow as long as it's used the same way. The difference between Light and Hand Crossbow is the -2 to shoot with one hand, which I believe you still have to take anyways without Hand Crossbow proficiency. You'll have to ask your GM because there's many rules for weapon enhancing, but very few about changing an item type.

Think of it like that: A dagger tied to a stick is not a spear. A large longsword is not a greatsword. Just because it's "kinda like that other thing" doesn't mean they're the same.

[SwitcherOccifer]

Wow, yeah. I often finding myself looking for a specific answer to a question I'm not sure how to ask. Thanks for both the answer and the question I should have asked.
I guess I'm trying to find RAW ways to essentially tie a dagger to a stick or add splitting to shirukins by machining weak points in the metal that breaks it apart in flight.
Personalizing a weapon at creation (and I feel silly for thinking this) wouldn't essentially grant a free feat, just reduce its cost. But, a "hand crossbow of aptitude" could be created as a +1 weapon with the help of the party rogue.
The other stuff is just RP fluff, really. I'm over thinking it.
Still. Thanks for the HUGE help.

[Gullintanni]

Wow, yeah. I often finding myself looking for a specific answer to a question I'm not sure how to ask. Thanks for both the answer and the question I should have asked.
I guess I'm trying to find RAW ways to essentially tie a dagger to a stick or add splitting to shirukins by machining weak points in the metal that breaks it apart in flight.
Personalizing a weapon at creation (and I feel silly for thinking this) wouldn't essentially grant a free feat, just reduce its cost. But, a "hand crossbow of aptitude" could be created as a +1 weapon with the help of the party rogue.
The other stuff is just RP fluff, really. I'm over thinking it.
Still. Thanks for the HUGE help.

I'm not sure if you're suggesting that the Artificer could create a,

+1 Hand Crossbow of Aptitude (+2 total enchantment), in which case, yes; or a,

Hand Crossbow of Aptitude (+1 total enchantment), in which case, no.

Any magical piece of weapon or armor must have a +1 enhancement bonus before you can add special magical properties to it.

[Telonius]

Yeah, this is a case of "ask your DM." I'd absolutely allow a player to build that kind of a weapons researcher. I'd suggest this as a method of figuring it out.

For any new ability you want to put on the thing, find a magical enhancement that does something equivalent. (If there isn't one, eyeball what you'd charge for the ability). To develop the weapon, charge what you would in time and gold (but not XP) if you were adding it as an actual magical enhancement. Reason being, you have to actually do the research and figure out how to create the thing, which is time-consuming and expensive; but it doesn't consume "life force" XP the same way making a magical thing would. I'd charge the same as a magical item because the thing will have a big benefit and a big drawback compared to the magical version, which roughly balance out. Benefit: it is not dispel-able. Drawback: it does not get through DR/magic, and does not get the bonuses to hardness and item HP that magical items usually give. You have the same +10 bonus limit as you would if the thing were a regular magic item. (At some point, you just can't put any more gizmos on it and still have it work).

I'd also say that anything you create like that works like the original item for you, but only for you. If you were proficient in the original, you're proficient in the modified version, since you were the one who made it. Otherwise, it's an exotic weapon. Anybody else who picks it up is going to take the nonproficiency penalty. (This includes people with that Master of Masks ability and other cute things to try to get around the restriction). The item will be your personal thing only; there is no market for making more of them.