GURPS version of Ghostly Reload D&D spell?

[Pursuivant]

FWIW, I've got a house rule that allows you to boost the effective ST (or whatever) of the forces powering a Dancing Object spell. That would allow the standard spell to cock a heavy crossbow in just 1 turn, or even "instantly" if you allow a Fast-Draw skill variant for fast reloading.

Spoiler:  

Spellcasting Options: For extra cost, multiple objects can be animated using Dancing Object, as long as they all remain in the same hex and cooperate to complete a single task. For example, the caster could animate a broom and a dustpan to sweep dust into the pan. Each additional item animated after the first multiplies the casting and maintenance costs by the same amount.

Each extra point of energy used to cast the spell boosts the spell’s effective ST by 5, or DX or Move by 1. For example, spending 4 points of energy to cast the spell can animate an object as if used by a man with ST 15, DX 11 or Move 6.

For double cost the Dancing Object can be made reprogrammable. In this case, by concentrating for a second while touching the subject, the caster can change the task the spell performs without needing to recast it.

For double cost, the Dancing Object can respond to feedback, so that it will slightly vary its motion depending on the situation, or will stop when given conditions are met, although the stopping conditions must be specified when the subject is animated.

Optional Rule: Skilled Dancing Objects. Subjects animated by the Dancing Object spell can be made to perform one or more tasks which require trained skill. In this case, cost to cast the spell is doubled and the animated object can only perform the task as well as the caster could himself, and at the same rate.

Dancing Objects in Combat: Since they cannot respond to their environment, items animated using the Dancing Object spell can’t make targeted attacks or use Active Defenses. But, a weapon animated using Dancing Object could be programmed to make Wild Swings or Wild Shots at a particular hex or line of hexes.

Clever use of the Link spell can be used to allow Dancing Objects to make attacks, but in such cases, the attack never has a skill level better than the Dancing Weapon’s effective DX, before modifiers to hit are taken into account.

A hypothetical Fast Reload spell would be a combination of Dancing Object + Great Haste, with reduced prerequisites and costs for shorter duration and specialized function. My writeup for "Dancing Reload" allowed that spell to be combined with Great Haste.

Your player is also forgetting the possibility of a spell which both cocks the crossbow and reloads it simultaneously - turning it into the magical version of a Repeating Crossbow.