There are literally millions of spears which meet your criteria. And if you are not going to count a jam as a failure, then a resharpening of an edge should not be counted as a failure either. IF you prefer we can make it a steel sword, say a Gladius?
10,000 rounds per barrel for 100 barrels would be a failure every 20 minutes at the Vickers 500 rounds per minute fire rate. Except 100 x 20 minutes is 2000 minutes, but that would take 33 hours. So 100 barrels over 12 hours is a failure every 7 minutes 12 seconds, which is only 4000 rounds between failures. A 1% failure rate on a per shot basis for 1,000,000 rounds would be 10,000 rounds per failure.
So it seems like you just gave a great example for supporting a 1% failure rate (for a weapon famous for its reliability, which infers a normal failure rate was higher), which results in a weapon failure, which can be fixed during the course of a battle, which is precisely the current model.
A stone spear is good for 1500 strikes before the point chips and needs to be replaced? Pull the other one, it has bells on. Granted, a steel Gladius was more reliable than stone, but it was also newer technology. It was also inferior to modern blades which are even less likely to break.
I specifically objected to a simple jam or stoppage costing MSP to clear, even if it does mean the weapon fails to fire. Random breakage should be expensive to repair, but a 1% failure rate is far too high. This is especially egregious with multi-weapon turrets where a single weapon failing requires overhauling the entire turret.
That was the combined totals for 10 weapons, so your firing rate calculation is off. 1 million rounds without a single jam or misfire is exceptionally good, which is what the Vickers is famous for.
Barrel changes aren't random failures, but planned maintenance. They also don't cost as much as a full replacement weapon system (including mount) to perform. While 10k round barrel life was top of the line, equivalent to the Browning M2, it wasn't newsworthy for a full-auto weapon. Modern cobalt lined barrels rated for 18k rounds are now available, if more expensive.
If the 1% failure rate is meant to simulate field maintenance rather than random breakage then it is still at least twice too expensive. Not replacing barrels on schedule should result in degraded accuracy and eventually range and reliability before the weapon becomes inoperable due to mechanical failure. Unless a major failure occurs it shouldn't cost any more than normal to get it working again when spare parts become available. Multi-weapon turrets are still being over-penalized as they pay for combined wear without benefiting from combined longevity. A quad turret should cost four times as much to overhaul, but it should also fire four times as many shots before needing it.
Weapon maintenance shouldn't be random but planned with increased chance of random failures as a consequence for putting it off, essentially like the overhaul system for ships but counting shots fired instead of running hours. A way to increase weapon endurance for an increase in price would add strategic options as well: Do you buy 5k round weapons to save money or shell out for 20k ratings to handle long engagements? Or split the difference with 10k guns?
Edit:
I don feel that such a malfunction rate is in line with what you expect from future technology.
You feel that way because you made poorly designed ships and you would rather blame the game than yourself. I know the feeling - every time I screw up in a game, my first instinct is to gripe at the game, and only later, with some introspection, do I realize where the fault (usually) really lies. It's a completely standard human reaction. Which is why Steve shouldn't rush to make any changes until enough data is gathered and some statistics put up.
So it seems like you just gave a great example for supporting a 1% failure rate (for a weapon famous for its reliability, which infers a normal failure rate was higher), which results in a weapon failure, which can be fixed during the course of a battle, which is precisely the current model.
Yes, Maxim is a bit of a poor example because it is indeed legendary for its robust design and reliability. There are also terrible firearms that malfunction all the time but those are generally commercial failures and drift away from public consciousness quickly.
But the whole spear vs gun issue is completely moot as it has nothing to do with the topic at hand. A better comparison would be a ballista vs a modern computer-controlled self-propelled artillery-cannon, something like the Panzerhaubitze 2000 firing the M982 Excalibur shells.
But that is also a moot point because Jorgen_CAB and Doren pointed out the real reason: so that orbital bombardment isn't too powerful - and I'll add that it also hampers kiting as the slightly-faster, the slight-outranging ship might now run out of MSP before the other side gets sniped to death.
Steve already changed it from 2% to 1% due to the test campaign so it's unlikely to be reduced even further, at least not without lot more evidence to show it as too punishing.
Beam weapons becoming too powerful for bombardment was a result of removing atmospheric protections against them, which IIRC was done to allow ground-based beam weapons to attack ships. I do agree that something needed to be done, but am not happy about how it hurts ship to ship combat, especially beam PD. If it is meant to simulate wear, then the 1% rate is reasonable but the repair cost is still too high and multi-weapon turrets are outright crippled.