5mm ammunition: What exactly is it?

[Sn1p3r187]

I keep wondering. From Fallout 1 to Fallout New Vegas, what exactly is 5mm ammunition specifically? I keep thinking about it. I'm stuck between it being 5.56 ammunition, 5.45 ammunition which is a Russian round, or just something completely different from it. What do you think? Is it its own type of 5mm ammunition?

 

[Willy]

I'm pretty sure 5mm is used in the minigun in game. Remington developed it to compete with the .22 but the 5mm ended up better then the .22 and the .17. From what I read it was just a varmint hunting round, weapons in that calibre seem to be pretty rare though. I really dont think it's gonna be on par with a 5.56. I guess it also could depend on where the creators got the inspiration for this round also.

 

[NovaRain]

I'd take 5mm as its own type of ammunition, purely made-up, not an alternative representation of real world 5.56mm (there's already .223) or 5.45mm.
But it's interesting to guess what its inspiration is. My guess is the dev (maybe Chris Taylor?) took Russian 5.45mm as inspiration.

Although there does exist a 5mm rifle round in real world: 5x44mm, the forerunner of British experimental 4.85mm round in 70s. You can check some pictures here:
http://www.bocn.co.uk/vbforum/threads/80801-4-85mm-Brit-Experimental-Ammunition
http://www.iaaforum.org/forum3/viewtopic.php?f=1&t=568

 

[Jimme John]

A niche varmint round akin to .22 developed by Remington in the 60's/70's. It failed miserably so they stopped producing it. Wonder why they chose such an odd round for the minigun.

 

[Sn1p3r187]

A niche varmint round akin to .22 developed by Remington in the 60's/70's. It failed miserably so they stopped producing it. Wonder why they chose such an odd round for the minigun.

I know. I find it just as odd. They were better off using .308 winchester for a minigun.

 

[G_P]

A niche varmint round akin to .22 developed by Remington in the 60's/70's. It failed miserably so they stopped producing it. Wonder why they chose such an odd round for the minigun.

I know. I find it just as odd. They were better off using .308 winchester for a minigun.

.308 (7.62 NATO) ammunition is quite heavy and takes up a lot more room than something in the 5mm range of ammo. It works great in mounted miniguns but in a man portable version would be way too heavy and bulky. It also has a lot more recoil than 5mm based ammo.
Fallout has .223 ammo so I'm surprised they didnt use that for the minigun.