Cataclysm-dda: Civilian .308 Winchester is more accurate than milspec 7.62x51mm M80.

[Marrim]

Describe the bug
.308 Winchester has 15 dispersion while 7.62x51mm M80 has 25.

To Reproduce
Steps to reproduce the behavior:

1. Spawn some ammo of the aforementioned types, compare dispersion values.

Expected behavior
Civilian .308 should have more dispersion than its military analogue 7.62x51mm M80.
I checked the jsons in the ammo folder, and for .223, the milspec variant (5.56 NATO) reads:

"relative": { "damage": -2, "pierce": 4, "dispersion": -10 },

However for .308 ammo the milspec variant (7.62x51 M80) reads:

"relative": { "damage": -2, "pierce": 4, "dispersion": 10 },

This is the reason I suspected a bug.

Screenshots
Not applicable

Versions and configuration(please complete the following information):

• OS: Ubuntu MATE (16.04 LTS)
• Game Version 0.C-31838-g769f1f6
• Terminal

Additional context
None

[kevingranade]

Civilian .308 should have more dispersion than its military analogue 7.62x51mm M80.

Source?

[Marrim]

It was that way before "copy-from" definitions were introduced. I only noticed because one of my old survivors used that ammo extensively. And if you look at the lines quoted above, it's pretty obvious why I came to think it's a simple typo in the json. What should have been -10 accidentally became 10.

[ghost]

From the jsons, showing that 556 is more accurate than 223,
it stands to reason its a typo that 762 is less accurate than 308.
And I understand from a game balance reason, military ammo being better.

from a realism standpoint though; I was bored and curious and did some googling, and the (oh-so reliable I'm sure / s) comment sections of various gun forums showed peoples anecdotal evidence of commercial 308 being MORE accurate than the military surplus 7.62.
Something about 7.62 being designed for dimensional tolerances in different gun barrels, and having more stopping power, when fired from machine guns. Wheras 308 being designed for hunting/competitions with stricter accuracy requirements.

If you can wade through the comment section where everyone is a marine/navy seal and wants to fight about it, here is where I read about it
https://www.ammoland.com/2017/06/7-62-nato-vs-308-winchester-ammo-whats-the-difference/

[Marrim]

From a game balance reason it's great that both types of ammo would have their downsides.
A commentary in the ammo definition would be prudent in that case.
Anyway, it's up to Kevin to decide, right?

[HeadWar]

Generally, military ammo is produced in vast quantities, by the lowest bidder. I wouldn't expect it to be better than civilian ammo.

In CDDA, in the machine gun calibres it is also a lot easier to get in large quantities, because of all the vehicle mounted machine guns.

[kevingranade]

It seems reasonable to reverse this on the basis of the change being a mistake in the first place