[swordtart]

Indeed, I was suggesting that this might be the only action that might allow you to improve the precision of the musket.

If you apply a skill cap, this could improve it by one. If you choose a maximum chance to hit this could increase it by one.

I also think that it is something that needs to be prepared for in advance by aquiring the equivalent of Match grade ammunition (probably casting it yourself with a custom mould and fettling it). With an imperfect ball, loading carefully won't help. Loading fast with a perfect ball may turn it into an imperfect ball.

From experience, a perfect ball also needs to be protected. Musket balls rattling around in a pouch quickly aquire flat spots (though interestingly it also knocks off the mould lines and sprue stubs). Cartridges provide adequate protection and allow you to carefully measure the powder in advance. They can also be weather protected more easily than loose powder.

Loading with a cartridge (with a correct size ball - undersized balls were used to speed up loading) can take longer than with a collar of bottles and loose ball so this may fit well the rule cited by Tomsdad.

You will also need to load your own in advance. Ordinarily cartidges are mass produced in factories and so are not tailored to a particular gun. This is ideal for regimented armies using a similar bore who want to fire quickly and cheaply, but not so useful for the targeteer who wants to maximise his chance of hitting.

Loading a mass produced cartridge forgoes the benefit of loading carefully as you have no control over the size of the ball, whether it was well formed, or the quantity and quality of the powder (which could vary significantly between cartridges of different batches and storage times). You also need to be wary of the manufacturer who may have cut corners to increase their profits (replacing a portion of the powder with soot or sawdust for example), especially as you can't really check a cartridge without opening it.