What Is This Bullet For?

Tallor · 10-09-2016, 04:39 PM

There's a lot of reasons why a bullet is designed one way or another. Weight, cost, its accuracy (based on its size vs the barrel's length), wounding channels, etc.

I understand some of the basics, like having carbines for light infantry and LMGs for support, but I don't understand what each bullet is actually ideal for. Let me explain.

The 5.56 NATO seems to be a popular ammunition for assault rifles, its slender profile allowing dozens of rounds to be stacked into a single magazine. It does about 4d+2 or 5d piercing damage, depending on carbine or rifle barrels. It's plenty enough damage to kill an unarmored human, and can penetrate DR 12 assault vests. Its power is limited, though, as it wont even scratch DR 23 trauma plates unless it's VERY lucky.

My guess is that the 5.56 isn't meant to go up against heavier, DR 25-35 troops, and meant to engage "non-plated" opponents and/or provide suppressing fire. Also, since lucky shots will still go through helmets and limb armor, the 5.56 is still a threat, enough to intimidate foes out of key locations.

I think with the solid numbers is easier to imagine what bullets could be used against, but I'm not sure my assumptions are all correct. What about "full-size" bullets like the 7.62x51? Were they used against plated targets, maybe thin-skinned vehicles? And what about the weird .338 Lapua Magnum that only appears in High-Tech once for the AI-AW sniper rifle?

sir_pudding · 10-09-2016, 04:44 PM

The real world doesn't use GURPS to make procurement decisions.

Tyneras · 10-09-2016, 04:46 PM

Armor is heavy and expensive, and most of the countries that can afford to equip their soldiers with it are currently allies one way or another.

So, equipping their soldiers for the threats they are likely to face, they use bullets designed allow high ammo capacity and be effective against lightly or unarmored opponents.

Ulzgoroth · 10-09-2016, 05:01 PM

5.56 NATO was developed at a time when personal armor was mostly not a thing beyond helmets. The M16 was first used in the Vietnam war...

It was supposed to be more controllable in automatic fire and let you carry more rounds, to give better results from personal automatic weapons than battle rifles. (Which, well...at least carrying more ammo worked out.) There were claims that any reduction in lethality from the smaller bullet would be counteracted by multiple hits.

Almost all major rounds predate significant prevalence of effective infantry armor, I think. That's a very recent phenomenon.

7.62x51 is a fairly direct descendant of WWI and WWII rifle rounds. It doesn't actually predate the intermediate-power rounds (when it was adopted, the British wanted an intermediate round instead, but the US insisted on full power), but it comes from a tradition that does. I think I recall punching through a standard helmet at a rather long range being one of its qualifications. As a rifle round it's not really anti-vehicle, though machine guns, especially with AP rounds, can certainly do a job on vehicles with no or very light armor, or punch through some cover.

A lot of the odd bigger rounds come out of sport shooting and/or hunting weapons. You could look it up online, but I strongly suspect that's where .338 Lapua Magnum has its origin. Of course, there's not that big a difference between a sufficiently rugged long-range hunting or target shooting rifle and a sniper rifle...

This last does not apply to .50 BMG, which was invented for heavy machine guns, or some similar rounds from elsewhere. Those usually are specifically anti-vehicle and/or anti-aircraft at root, though they usually do a more than adequate job when turned against infantry.

sir_pudding · 10-09-2016, 05:13 PM

Quote:

Originally Posted by Ulzgoroth

5.56 NATO was developed at a time when personal armor was mostly not a thing beyond helmets. The M16 was first used in the Vietnam war...

And warehoused by NATO countries in such large quantities that it's not cost effective for large institutions to change to different round. Which is a factor that's never going to show up in an RPG's statblock.

Ulzgoroth · 10-09-2016, 05:32 PM

Quote:

Originally Posted by sir_pudding

And warehoused by NATO countries in such large quantities that it's not cost effective for large institutions to change to different round. Which is a factor that's never going to show up in an RPG's statblock.

I guess I focused particularly on the point of what the rounds were designed for, which is only one of the thrusts of the OP.

But yeah, other historical and current factors are very relevant to why and how it's used now. And neither necessarily matches up to what the round is 'ideal' for, if anything. There are a lot of aspects to this question.

clu2415 · 10-09-2016, 07:27 PM

Quote:

Originally Posted by Tallor

And what about the weird .338 Lapua Magnum that only appears in High-Tech once for the AI-AW sniper rifle?

The .338 Lapua Magnum was developed to set long range precision shooting records. It is the caliber used to set the current long range sniper kill in combat at a range of around a mile and a half.

RyanW · 10-09-2016, 09:19 PM

Quote:

Originally Posted by Ulzgoroth

A lot of the odd bigger rounds come out of sport shooting and/or hunting weapons. You could look it up online, but I strongly suspect that's where .338 Lapua Magnum has its origin. Of course, there's not that big a difference between a sufficiently rugged long-range hunting or target shooting rifle and a sniper rifle...

Nope. The .338 Lapua is a purpose designed military sniper cartridge, though it has been adapted to big game hunting.

Colarmel · 10-09-2016, 11:02 PM

The father of the 5.56 NATO is the .223 Remington. 5.56 is a higher pressure round, but the two rounds are similar enough that many weapons can use them interchangeably.

The .223 Remington is what's called a varmint round. It's good for smallish animals up to about a coyote or a hog. Some people use them for Deer, but that's a contentious thing. Lots of people think it doesn't have enough stopping power for a humane deer kill. The switch to 5.56 is driven by lower felt recoil, thus more shots on target, and more capacity.

7.62x51 was born from the .308 Winchester. In this case the hunting round has slightly higher pressure, but they're genuinely interchangeable. .308 is a larger game round, they can be used for anything in North America with good effect.

Another major factor in design and the switch from .308/7.62 to .223/5.56 was that one of the demands for the 7.62 was the capability to engage effectively at pretty extreme ranges. 5.56 was selected with 300 yds as the typical combat distance.

The Wikipedia pages on both rounds actually have some very solid design information.

Tomsdad · 10-10-2016, 04:19 AM

Quote:

Originally Posted by Tallor

....

I understand some of the basics, like having carbines for light infantry and LMGs for support, but I don't understand what each bullet is actually ideal for. Let me explain.
...

I think the point is ideal is the wrong way to look at this, most bullets* are a compromise due to conflicting desires and needs. So instead of this bullet is ideal for "X", it's more this bullet ticks more boxes than the rest in the situation we're most likely to find ourselves in.

Now what's an accepted comprise point changes as needs change and technology changes, but when you include wider the context to include large scale procurement etc you end up compromising again.

*and widely adopted guns as well come to that

10-09-2016, 04:39 PM	#1
Tallor Join Date: May 2016	What Is This Bullet For? There's a lot of reasons why a bullet is designed one way or another. Weight, cost, its accuracy (based on its size vs the barrel's length), wounding channels, etc. I understand some of the basics, like having carbines for light infantry and LMGs for support, but I don't understand what each bullet is actually ideal for. Let me explain. The 5.56 NATO seems to be a popular ammunition for assault rifles, its slender profile allowing dozens of rounds to be stacked into a single magazine. It does about 4d+2 or 5d piercing damage, depending on carbine or rifle barrels. It's plenty enough damage to kill an unarmored human, and can penetrate DR 12 assault vests. Its power is limited, though, as it wont even scratch DR 23 trauma plates unless it's VERY lucky. My guess is that the 5.56 isn't meant to go up against heavier, DR 25-35 troops, and meant to engage "non-plated" opponents and/or provide suppressing fire. Also, since lucky shots will still go through helmets and limb armor, the 5.56 is still a threat, enough to intimidate foes out of key locations. I think with the solid numbers is easier to imagine what bullets could be used against, but I'm not sure my assumptions are all correct. What about "full-size" bullets like the 7.62x51? Were they used against plated targets, maybe thin-skinned vehicles? And what about the weird .338 Lapua Magnum that only appears in *High-Tech* once for the AI-AW sniper rifle?

10-09-2016, 04:44 PM	#2
sir_pudding Wielder of Smart Pants Join Date: Aug 2004 Location: Ventura CA	Re: What Is This Bullet For? The real world doesn't use *GURPS* to make procurement decisions.

10-09-2016, 04:46 PM	#3
Tyneras Join Date: Oct 2007 Location: Kentucky, USA	Re: What Is This Bullet For? Armor is heavy and expensive, and most of the countries that can afford to equip their soldiers with it are currently allies one way or another. So, equipping their soldiers for the threats they are likely to face, they use bullets designed allow high ammo capacity and be effective against lightly or unarmored opponents. __________________ GURPS Fanzine The Path of Cunning is worth a read.

10-09-2016, 05:01 PM	#4
Ulzgoroth Join Date: Jul 2008	Re: What Is This Bullet For? 5.56 NATO was developed at a time when personal armor was mostly not a thing beyond helmets. The M16 was first used in the Vietnam war... It was supposed to be more controllable in automatic fire and let you carry more rounds, to give better results from personal automatic weapons than battle rifles. (Which, well...at least carrying more ammo worked out.) There were claims that any reduction in lethality from the smaller bullet would be counteracted by multiple hits. Almost all major rounds predate significant prevalence of effective infantry armor, I think. That's a very recent phenomenon. 7.62x51 is a fairly direct descendant of WWI and WWII rifle rounds. It doesn't actually predate the intermediate-power rounds (when it was adopted, the British wanted an intermediate round instead, but the US insisted on full power), but it comes from a tradition that does. I think I recall punching through a standard helmet at a rather long range being one of its qualifications. As a rifle round it's not really anti-vehicle, though machine guns, especially with AP rounds, can certainly do a job on vehicles with no or very light armor, or punch through some cover. A lot of the odd bigger rounds come out of sport shooting and/or hunting weapons. You could look it up online, but I strongly suspect that's where .338 Lapua Magnum has its origin. Of course, there's not that big a difference between a sufficiently rugged long-range hunting or target shooting rifle and a sniper rifle... This last does not apply to .50 BMG, which was invented for heavy machine guns, or some similar rounds from elsewhere. Those usually are specifically anti-vehicle and/or anti-aircraft at root, though they usually do a more than adequate job when turned against infantry. __________________ I don't know any 3e, so there is no chance that I am talking about 3e rules by accident.

10-09-2016, 11:02 PM	#9
Colarmel Join Date: Aug 2012 Location: Northeast Kansas	Re: What Is This Bullet For? The father of the 5.56 NATO is the .223 Remington. 5.56 is a higher pressure round, but the two rounds are similar enough that many weapons can use them interchangeably. The .223 Remington is what's called a varmint round. It's good for smallish animals up to about a coyote or a hog. Some people use them for Deer, but that's a contentious thing. Lots of people think it doesn't have enough stopping power for a humane deer kill. The switch to 5.56 is driven by lower felt recoil, thus more shots on target, and more capacity. 7.62x51 was born from the .308 Winchester. In this case the hunting round has slightly higher pressure, but they're genuinely interchangeable. .308 is a larger game round, they can be used for anything in North America with good effect. Another major factor in design and the switch from .308/7.62 to .223/5.56 was that one of the demands for the 7.62 was the capability to engage effectively at pretty extreme ranges. 5.56 was selected with 300 yds as the typical combat distance. The Wikipedia pages on both rounds actually have some very solid design information.