Reloading breechloaders in a single second with one weird trick. Historians hate him!

[Polydamas]

Originally Posted by ravenfish

Should that imply the cost ought to be rather higher than Low-Tech gives? A high cost would adequately explain why similar pieces did not see use on the battlefield, despite a rate-of-fire that is impressive even without the min-maxing discussed in this thread.

I would want to do the research in period sources. Most prices in GURPS books are based on other prices in GURPS books, or come from catalogues and online stores during the writing and playtest.

It does seem like this should be more expensive than a basic wheelock rifle, and at least as expensive as a basic sword. The Royal Armouries compare the breech mechanism to a mid-19th-century Jacob Snyder design.

[johndallman]

Originally Posted by Calvin

Isn't that exactly the figure I arrive at for the paper cartridge example? Granted, I'm assuming successes on the relevant rolls, while you include the figures for a failed Fast-Draw.

Yes. I was just trying to unpack it a little more to show the reasoning.

[Pursuivant]

For a Dungeon Fantasy or Steampunk/Gearpunk campaign, this level of fire is entirely reasonable given a a highly skilled shooter (possibly with the Gunslinger advantage), a "dropping block" or "rolling block" type breech which can be opened or closed quickly, the equivalent of TL6+ steel and machining tolerances, and powder which causes significantly lower levels fouling than was the case historically. With magic or access to suitable quantities of handwavium anything is possible.

Realistically, the main problem with keeping up this rate of fire is black powder fouling which makes it progressively harder to open and close the breech.

If the breech isn't completely closed or wear causes any imperfections there is a risk of burning powder working its way through the imperfect seal, shooting jets of hot, fast-moving gasses back into the shooter's face.

Due to progressive fouling each shot after the first slightly increases loading time and reduces Malf to the point that the gun soon needs to be carefully cleaned and inspected before can be safely and efficiently used again.

The same thing applies to self-priming guns where priming powder was stored in a reservoir and a simple lever or screw action dumped a new priming charge into the pan, but with the added risk that any blowback when the powder in the pan ignited could blow up the priming powder reservoir.

The realistic lifespan of such a weapon might be just a few hundred or a few thousand shots, far less than could be expected from a slower-firing conventional weapon. Add in the cost and higher skill levels required to make such a gun and it becomes a rare and expensive specialist's weapon rather than standard issue. That's the reason that Henry VIII had access to what effectively amounted to experimental TL5 technology at TL4.

Historically, there cases where troops armed with early breechloaders or airguns were able to briefly generate far higher rates of fire than the contemporary norm, but operational factors and expense of maintenance and procurement always limited them to being expensive novelties.

If you want to be ultrarealistic about it, quick "snap shots" with any sort of non-caplock black powder weapon are impossible because you need to hold position and aim for a fraction of a second while the priming powder ignites the main charge. This limits RoF to 1 or less for any single-barreled weapon. The only way to boost RoF to 2+ is to add a lock to each barrel of a multi-barreled weapon which greatly increases expense, weight, Min ST and Bulk. (This delay in ignition time is also a good reason to allow Active Defenses against BP gun shots as long as you can see the flash or smoke from the priming charge igniting.)