# Advantages of Ball bearing projectiles over Bullets?

I was wondering if one of those metal ball bearings would be useful for some reason as a projectile fired by a gun. Obviously, in terms of killing power they would lose out to bullets as bullets are specially designed to soar through the air. A ball bearing would not be a good aerodynamic shape to fly through the air and it doesn't have a good shape to inflict damage on an opponent.

However are there any advantages of using ball bearings instead of bullets? Could ball bearings allow it to do special things bullets cannot(like carry a small explosive payload, since I couldn't find any bullets that literally exploded)?

I do know that muskets and aquebuses seem to have shot round projectiles. Which have been of course phased out by modern bullets.

• You're talking about a HEIAP round - a quick search of "explosive bullets" will lead you to it, and they already exist in real life. An example is the Raufoss Mk 211 round, which is a bullet which carries a small explosive payload, and on a good hit, will explode. – Aify Sep 10 '16 at 8:06
• @Aify couldn't find it when I searched for explosive bullets... Anyway it was only an example – Skye Sep 10 '16 at 8:08
• Then the answer is an easy "No, there are no advantages" - if there were any that made a difference at all, bullets would not be used so widely. – Aify Sep 10 '16 at 8:13
• The answer to things like this is always relative to what you mean to use them for. If You mean for training purposes I'd much rather use a ball than a bullet, because they are less lethal, but give you that sting that makes you question why you are participating in something that allows people to shoot projectiles at you... – Durakken Sep 10 '16 at 15:17
• Shotgun charges, especially loads like 0 and 00 magnum shot are essentially several ball bearings (steel or lead spheres) fired out of a smooth bore weapon. You can draw you own conclusions as to lethality. Specialty rounds have different shapes based on what they are supposed to do (deer slugs have shapes to improve their aerodynamics, while door breaching charges are cylinders of compressed material which holds together until it shatters a lock or hinge, then disintegrates. – Thucydides Sep 11 '16 at 5:30

## 12 Answers

About the only advantage a spherical projectile has over a pointed bullet is a lack of facing. This is why they were used prior to the Minie ball in muzzleloaders (the round ball was smaller than the diameter of the smoothbore barrel so it could roll down more easily, for a faster reload time) So if your firing mechanism needs the bullet to be able to be firing in multiple directions, a spherical shape may be an advantage.

Of course I can't really imagine how a mechanism like this could work, unless the round projectile is suspended in a magnetic field and could be launched in any direction.

Another advantage is when firing a cluster of bullets at once, like in a shotgun. The individual projectiles are held in place by wadding, but once they leave the barrel they are ejected from the wadding. Round projectiles are probably the most space efficient way to pack the rounds into the wadding and have better aerodynamics than an oblong shape since they won't have a spin imparted by a rifled barrel (there are flechette shotgun rounds with dart like projectiles but these are niche cartridges).

• «Round projectiles are probably the most space efficient way to pack the rounds into the wadding» No. That is a well studied topic in mathematics. It's long been known that oblate spheroids pack better (iirc) and was recently proven that a spheroid with different dimentions on all 3 axis pack the best. – JDługosz Mar 21 '17 at 2:39
• @JDługosz Don't cubes have the best packing efficiency? And yes, spheres are about the worst in terms of packing efficiency in terms of regular solids. – Tritium21 Mar 21 '17 at 6:06
• The studies are considering round-ish shapes. – JDługosz Mar 21 '17 at 8:04
• You guys have to consider WHAT you are packing. In a discussion of ball bearings (or pellets) versus conical bullets, you can pack more spheres than bullets, since you can't orient the bullets in anything other than point forward (unless you want them to tumble all over as soon as they hit air resistance). Plus you have to consider how you pack the wadding, how difficult it is, versus the cost. Uniform spherical pellets with no orientation require the most simple wadding structure (and probably less of it versus cubes, oblong shapes, or whatever). – Jason K Mar 21 '17 at 13:30

Paintballs are spheres, not bullet shaped. I suppose this offers an advantage in a continuous hopper-loading system, as each projectile can be dropped in and they are stored in a loose pile. Some BB guns are the same way, with a plain pile of spheres that funnel into the loading mechanism. They are constant width in any orientation so the “plumbing” that moves the projectiles around is very simple.

Bullets require magazines to keep them in the correct orientation and moving them in different directions requires different mechanisms of handling.

So an advantage of a spherical projectile would be ease of bulk loading.

An advantage I can think of is availability; I don't know the purpose of your question, but ball bearings are easier to acquire than bullets. Add to that a greater stopping power, generally speaking, cause of the more blunt area of impact.. but apart from those, I don't see many advantages. Usually they're solid steel, so it'd be more difficult to use them on grooved barrels and give the spin to stabilize them, this added to the less aerodynamic shape, leads to a shorter useful range.

• I think at the point were your manufacturing things to the tolerances of a more modern bullets it's not really more efficient to make it a sphere rather than an oblong pointed shape. – Marky Sep 11 '16 at 0:38
• I'd argue that a soft lead bullet that is going to expand after hitting is going to have more "stopping power" than a hardened steel ball bearing. The ball bearing may have a "more blunt area of impact" at the first moment of contact, but a well-designed bullet is going to quickly mushroom out much larger in order to transfer as much energy to the target as possible. – Salda007 Mar 21 '17 at 7:02

This is pretty much how a Claymore mine works: by blasting steel ball bearings in a particular direction. The ball bearings have an initial velocity of about 1200 $m/s$, which is actually higher than a 5.56mm NATO round. However, as you pointed out, they're not very aerodynamic, so their range is much shorter than a bullet (about 100 m). So, I'd say there's no point in using ball bearings instead of bullets, except in ambush weapons like a mine. As MarkRipley points out, their short range actually helps here, because they're not as likely to hit something they shouldn't (like an ally who's 300m away), but they still have a wide area of effect.

An alternative, of course, is if railguns are common weapons. If so, ball bearings would be much lighter than bullets, so you could carry more ammo. However, they'd still have limited range compared with a bullet.

• In the case of claymore mines (and shotguns) the purpose is to get a lot of projectiles moving in a wide spread of target area. These weapons both use round projectiles and are not designed to give the longer range that a spinning bullet gives, but rather to have a shorter range wide area of coverage. With non-precise aiming, a weapon with both long range and wide dispersion may cause problems due to unintended hits on anything in the dispersion pattern. So in the case of claymores and shotguns, the shorter range is actually an advantage. – Mark Ripley Sep 10 '16 at 8:38
• @MarkRipley Good point, I'll add that in. – Philip Rowlands Sep 10 '16 at 8:51

Ease of manufacture was my first thought, but I'm not entirely sure if that really holds for modern machining...

My second thought was ricochet. A ballbearing would likely have a more predictable and possibly more powerful ricochet as it wouldn't tumble after the initial impact. Imagine blasting hard rubber shot at an angle down a concrete hallway.

The reason for elongated bullets is that: (1) They provide higher sectional density that reduces drag induced slowing. (2) They facilitate longer more streamlined ogives that, surprise, also reduces drag. (3) Their higher sectional density increases penetration.

There is not any reason a sphere and an ogival-cylindrical projectile can not have the same hemispherical nose, for example a round nosed bullets.

A sphere that is not deformed either prior to or after firing does not require gyroscopic stability to prevent its yawing. On the other hand nothing is ever perfect and even a small blemish on anon rotating sphere can cause it to veer to one side or another and once that starts it continues increasing like a tennis ball hit with a slicing blow. Because of this rockets and arrows use fins to impart a very slow rolling motion. This is not to keep the projectile nose forward as does a rapid spinning that imparts gyroscopic stability to a bullet. It merely insures that the deviation does not always remain in the same direction ever increasing. For example as the projectile rolls 180 degrees the deflection changes direction by the same 180 degrees reversing and neutralizing the direction so a left hand veer becomes cancelled out by a right hand veer.

Most airguns (for what I know) shoot either Ball Bearings (BBs) or pellets. That, I think, should be your advantage since airguns can't really fire bullets well. So your advantage of using a BB would be that you don't need gunpowder to shoot your projectile.

If you want some bullet that explodes, anything 20mm and higher with the label "High Explosive" would work.

It could work like a small fragment effect grenade. You launch/fire it using a rifle, it moves rather slowly and explodes after a distance. It should have some explosive inside. It might be used as distant shotgun, making sure lots of people got hit. Damage wont be much. If you don't care about ethics, use poison for bullets.;

Here is a fact: There is only three significant advantages to using a round(spherical) bullet/ball bearing over shaped bullets. But the most important factor you must utilize for these facts to be true, is that all materials and "parameters" must be equal except for the shape(obviously). Brief explanation: both objects must be made of the same material and the exact same amount. Which equates to the identical weights and identical volume also known as square footage/area/mm...etc, regardless of shape. In other words, to be easier a fair comparison. These are what the data considers three SIGNIFICANT advantages are: SIGNIFICANT being the key word as it is the only part that is opinion and not Factual. See Below:

1. A Spherical object is only more effective in short range for impact damage (not piercing): less than 30 yards.
2. A Spherical object will Always have a larger impact and foot pounds of energy(joules) on a direct hit within short range. This is because the blunt force is one hundred percent equal regardless of material. Lead spreads equally in all directions giving the widest footprint and FPE. Steel doesn't doesn't spread but it's imprint will always be larger equating again to a higher FPE(Blunt Force).
3. It is much cheaper to produce(you could by 750 Ceramic coated steel ball bearings for about \$30). Examples of proof: Shotgun slugs, Slingshots, Short Range explosive devices with ball bearings. ETC.

Please Note: This is based upon current technology. ie. A large catapult 500 years ago was considered long range(before shaped bullets), but now would be considered a short range weapon. I only state this because I can already hear someone stating a catapult will work better with round objects. Which by the way is no longer true, because current technology can use rifled barrels and bullets with catapult designs that make them more effective at long range but less effective at Short range(as stated). This is why modern slingshots have been able to cause more harm than 9 mm handguns at Short Range and there are legislators trying to pass legislation to require licences.

Hope this was helpful to others.

Data from an MIT Controlled Study(non-variable). Methodology - Quantum Physics. Mathematical equations. Applied Technology.

• Great post. Can you edit in a link to the study you mention? – kingledion Sep 15 '18 at 0:01
• The study is not available to the public, nor is it posted anywhere to my knowledge. 70% of it was funded by the government along with a contract that they had first right of refusal to acquire the study. Needless to say, the option was utilized. I only know about it because I was part of the group that did the study. I had to sign 4 NDA's, and 1 of the 4 expired about 1 1/2 years ago. It's expiration allows me to release a very limited amount of the factual conclusions that were developed by the Study. The other 3 NDA's apply to the Methodology and they have no time limit. – Proto Consulting Sep 16 '18 at 7:59
• New Mathematical Equations were developed from Quantum Physics. Those equations were for Applied Technology......I'm sure you can figure out which department of government wanted the study although that was not disclosed to us. You could Google Railguns and see how rapidly they have progressed from a short range weapon to a long range weapon. I only mention this because the projectile of preference is Spherical. I have my opinion as to what is being developed, how it would be applied, and what vessel/vehicle it would be utilized on. That's as much as I can say. Don't want gov. @ my door – Proto Consulting Sep 16 '18 at 8:14

Reuse

Bullets have pointy shape which make them easily damaged at impact, and so unusable for a second time. Ball Bearings dont have any pointy heads, the force on impact will be distributed over the surface because of round shape - enabling a second time usage.

Obviously this is not for combats - you dont want your enemies to use your bullets back on you. Following are some non-combat situations where ball bearings may be preferred on bullets.

1) In animal hunting, as sports or for food. The animals are not going to fire your missile weapons back at you.

2) Practise Shooting. Instead of your NEW trainees wasting bullets each time they fire on a dummy target, make them use ball bearings. Once you are reasonably sure that the trainees can handle hard military life - both physically and emotionally - you let them use bullets for their shooting practise. This save resources because of reuse of ball bearings, and also because of more efficient production of ball bearings compared to production of bullets.

Come to think of it, even in combat ball bearings will be preferred on bullets, because of their more efficient production, provided either or both of following:

1) Your enemies didnt know in advance that you can use ball bearings instead of bullets, or for whatever reason didnt prepare for it, AND cannot make/acquire guns of same caliber as diameter of your ball bearings (for example your enemy unit is too small to devote resources in constructing furnaces for rifles making/overhauling, and cannot get reinforcments). If you are facing many such small enemy units you can take them out one by one and reuse your ball bearings as you go.

2) Your enemy cannot collect ball bearings fired on it because they passed over its troops' heads to some inaccessible terrain.

All the answers to date seem to have missed the (IMH)) glaringly obvious disadvantage of using ball bearings as bullets. Bearings are made of very hard steel, so they will wear longer. Firing hard steel projectiles though a gun barrel will wear it out much quicker than using soft lead or copper-jacketed bullets.

Another disadvantage is that bullets are often designed to spread on impact, causing more damage (e.g. https://en.wikipedia.org/wiki/Hollow-point_bullet ), where a hard steel projectile might pass straight through, causing less damage.

A ball bearing would not be a good aerodynamic shape to fly through the air...

Untrue. A sphere is uniformly aerodynamic—look at the shape of a drop of water. The reason bullets are elongated is to provide surface area for the rifling in the barrel of a gun to add spin to the bullet, to ensure it flies in a straight line. Without rifling, the bullet, whatever the shape, will easily be moved aside by air currents.

...and it doesn't have a good shape to inflict damage on an opponent.

Untrue. A sphere's centre of mass is always at right angles to any line parallel to its surface. You can't get better transfer geometry than that.

However are there any advantages of using ball bearings instead of bullets? Could ball bearings allow it to do special things bullets cannot(like carry a small explosive payload, since I couldn't find any bullets that literally exploded)?
Hollow point bullets already do that, as do armour piercing shells. The only reason we use conical bullets instead of spherical ones is to take advantage of rifling to improve accuracy. Otherwise, it's far easier to manufacture balls than specially shaped metal slugs.

• There are many things in this answer that are just plain wrong. Suffice to say that there are many reasons why "bullets" are better than "balls", of which rifling is only one. – Lord Dust Sep 10 '16 at 18:01