Binary propellant and Standard TL 8 guns?

[Anthony]

Originally Posted by hal

Part of the problem too is that if you stockpile ammunition for war time use, switching to a new system for ammunition causes logistics issues. Then there is the investment required to stockpile the new munitions. I can't help but wonder if that is one of the reasons that the G11 was scrapped, aside from the reunification of Germany and budget constraints etc.

"Not enough improvement to be worth the trouble" has been the fate of many new schemes for small arms. This is also the likely fate of any schemes for military small arms that are not 5.56mm.

[hal]

Originally Posted by Anthony

"Not enough improvement to be worth the trouble" has been the fate of many new schemes for small arms. This is also the likely fate of any schemes for military small arms that are not 5.56mm.

I started to ask what happened to the Future Warrior or Land Warrior program, but net searched the question and got my answers. It has apparently become the Nett Warrior program (in honor of Robert B. Nett). I find it interesting that they're using improved cell phones as part of the equipment per one Wikipedia article (and who knows how much to trust that!). But I'm guessing then - that it is best to ignore the binary propellant, and the Electrothermal-chemical as well. Again, it uses as a baseline, the caseless rounds for what kind of damage it offers.

Frankly? I think the best route to take with this is to apply the ETC rules to ANY conventional round as it appears to make the combustion of propellant more optimized. Otherwise, like the Binary, too "new" and probably not worth considering for anything save perhaps specialty weapons (such as a sniper rifle for example).

Perhaps the best thing to do is simply use TL 8 guns in a TL9 campaign on the premise that some of the TL 7 guns are still in production and use today.

[Fred Brackin]

Originally Posted by hal

example. A simple "does same damage as High Tech guns, but adds +1 damage and increases range by 1.3 might fit the bill.

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You already have the 10mm doing 1 pt more damage than the .40 S&W (though the SJGames caliber is actually older than the .40 S&W). similarly the 15mm looks like a modestly improved Desert Eagle.

You might want to alter a few things. The 10mm has Rcl 3 as a conversion artifact but 4e Rcl is a more severe drawback than the 3e stat. The 7.5 mm could be upgraded to an 8 and that would get rid of the "P- curse".

Then your new 8mm actually would replace compact 9mm Parabellums and a holdout version would replace .380s.

If you wonder what might push the military into caseless ammo I think it might be a new SAW weapon. Judging from HT stats caseless ammo actually is half the weight of the cased variety. Doubling your SAW gunner's ammo load might be the thing that's worth the trouble.

[hal]

Hi Fred,
If I were to go the route you're suggesting, which isn't a bad thing to do overall...

I suspect that I'd probably try out the GunsGunsGuns design sequence to see if they're even close to what would happen using real world data. I've already noted that when designing the bullet weights using their generic formulas for sphere, elongated sphere (pistol bullets) and the bullet rules for rifle bullets, they don't exactly match the real world information. Of course, real world physics being what it is, has different shapes for the bullets that don't exactly match the simplified scheme of things done by Greg Porter. However, he does suggest ratios of bullet lengths and propellant weights to bullet weights etc. I think he suggest and 8:1 ratio for bullets to propellants for caseless (and darned if that isn't close to the G11 stats by the way).

If his formula works? We can pick bullet weights for the most part, velocities we wish to achieve, and determine whether or not the propellant energy in joules and receiver efficiency works or not. Then, it would be simple enough to use Doug's formula for damage.

I've heard people dismiss Greg Porter's design system, so I don't know how well it would work. Something to do for tomorrow I guess. It will keep me out of mischief and maybe not say anything here in the forums for a couple of days. ;)

[mlangsdorf]

Originally Posted by hal

Maybe what I should do is get the actual max ranges listed for actual guns, and plot them as data points or create a spreadsheet that lists the ranges as well as the velocity of the round from CARTRIDGES OF THE WORLD. That in turn might give me a way to figure out the max damage range. (in a doubtful voice) That might work with 1/2 damage ranges as well, maybe. *cough*

I've put together a spreadsheet that estimates drag deceleration for velocity and then approximates vertical and horizontal velocity, acceleration, and distance traveled for about 300 delta-Ts*, and delta-T is configurable (so I use delta-T = 0.05 for pistol bullets and delta-T = 0.5 for 16" cannon shells). It can calculate maximum range and 1/2d for any angle of fire between 1 degree and 89 degrees. If you're interested and don't want to reinvent the wheel, I'll pull it into it's own spreadsheet and share it.

I checked the numbers versus US naval cannon, and the numbers look close enough - within 5-10% of the published maximum ranges.


* You can add more cells, but recalculating through 300 columns already takes a while.

[hal]

Originally Posted by mlangsdorf

I've put together a spreadsheet that estimates drag deceleration for velocity and then approximates vertical and horizontal velocity, acceleration, and distance traveled for about 300 delta-Ts*, and delta-T is configurable (so I use delta-T = 0.05 for pistol bullets and delta-T = 0.5 for 16" cannon shells). It can calculate maximum range and 1/2d for any angle of fire between 1 degree and 89 degrees. If you're interested and don't want to reinvent the wheel, I'll pull it into it's own spreadsheet and share it.

I checked the numbers versus US naval cannon, and the numbers look close enough - within 5-10% of the published maximum ranges.


* You can add more cells, but recalculating through 300 columns already takes a while.

I would love the spreadsheet please. Email me via Forums, and I'll send back a response to the email you tell me to respond to. Once we open up channels, we can discuss how to make your spreadsheet work faster via macros if you want (think VBA when you see the word Macros, and think VB.NET dumb cousin when you think VBA).

Thank you for the offer, much appreciated!

[Rupert]

Originally Posted by hal

Maybe what I should do is get the actual max ranges listed for actual guns, and plot them as data points or create a spreadsheet that lists the ranges as well as the velocity of the round from CARTRIDGES OF THE WORLD. That in turn might give me a way to figure out the max damage range. (in a doubtful voice) That might work with 1/2 damage ranges as well, maybe. *cough*

It won't give a terribly exact maximum range, due to the complex interaction of ballistic co-efficient, velocity, and maximum range (and Cartridges of the World doesn't list BCs) - this is why heavy, slow bullets often have a greater maximum range than light, fast bullets first from the same rifle.

As for 1/2D range - you'll have a similar problem, with the added issue that 1/2D range doesn't match any simple real life 'thing

[Rupert]

Originally Posted by Anthony

"Not enough improvement to be worth the trouble" has been the fate of many new schemes for small arms. This is also the likely fate of any schemes for military small arms that are not 5.56mm.

Indeed, especially as what really matters is selling the new weapon and ammo to the US military, and their last major requirement for a new infantry rifle, for the ACR trials, required such an improvement in hit chance that the only realistic way of meeting it with a small arm would be to use a belt-fed machinegun. Of course, since then they've been moving to weapons that are worse than the M16A2 at the long-range accuracy part of the requirement, and without bothering with full trial and tender processes, so it seems they've decided that the ACR requirements were in error (not that they've actually said this officially).

[hal]

Originally Posted by Rupert

It won't give a terribly exact maximum range, due to the complex interaction of ballistic co-efficient, velocity, and maximum range (and Cartridges of the World doesn't list BCs) - this is why heavy, slow bullets often have a greater maximum range than light, fast bullets first from the same rifle.

As for 1/2D range - you'll have a similar problem, with the added issue that 1/2D range doesn't match any simple real life 'thing

What I am thinking is that if the spreadsheet that was mentioned upstream from here is something that gives the rate of deceleration for a given bullet by mass and cross section, I think I have the means for determining what the 1/2 damage range is...

The formula that Doug gave us earlier in his spreadsheet can be made to solve for 1/2 damage value along with Velocity, as the bullet mass remains the same. Knowing how fast a bullet's speed will decline to meet that half damage velocity might be the other piece of the puzzle. Using the old displacement formula for 1/2 AT^2 to determine how far the bullet travels from the muzzle of the gun until it reaches the velocity for half damage might be a close enough value to be viable.

Maybe. I'd have to experiment with it to see how well it works. :)

[DouglasCole]

The spreadsheet already has Max range and 1/2 D range in it, by the way.

If you're working with Ballistics Model July 30-2013, which is I think my newest one:

The 1/2D and Max Ranges for a projectile are listed in cells D36 and D37, explicitly. The 1/2D range is based on an exponential decay using sectional density as the primary variable. It's not bad, though a full ballistics model would of course be better. It will tend to underestimate the 1/2D ranges of big, heavy projectiles that start subsonic and stay that way. For GURPS case, it probably won't matter.


The Max Range is a fitting parameter whose provenance I simply do not recall. I'm sure I did a model regression on real projectiles max ranges with the parameters I calculated, but this was a long, long time ago.

If you don't have the most recent version, ping me.