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  #1  
Old 06-02-2010, 01:31 PM
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22LR bullet shapes



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I always wondered why 22LR bullets have rounded dull tips vs. the sharp aerodynamic tip like the 17 or the typical centerfire rifle bullet. Wouldn't a pointed bullet help with wind resistance?
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Old 06-02-2010, 01:38 PM
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The pointed tip is only an advantage when you're supersonic. Since standard velocity for a .22 is subsonic, the noses were originally Round, not conic. That also helps with feeding.

Sure, there are high-velocity .22 rounds that are supersonic - but the difference in nose is not a huge difference, and staying rounded helps keep things historic, both for reasons of aesthetics and for feeding.

Also, imagine what sort of cone it would take to keep a .22LR within OAL measurements... and consider what it would do to the weight of the bullet.
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Old 06-02-2010, 02:01 PM
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My guess is that a pointed lead 22 bullet would be too fragile and subject to damage. It would also likely create feeding issues in many 22 firearms. There is also the potential issue of rounds going off from tubular magazine rifles if the pointed bullets were used. Lever Revolution for 22 rimfires.
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Old 06-05-2010, 05:31 PM
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I don't think that it would be an issue in a tube mag, as the .22lr is a rimfire cartridge, and therefore would need an impact on the rim, which a pointed bullet wouldn't provide.
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  #5  
Old 06-05-2010, 05:36 PM
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I suppose it would be hard to keep a long thin point of soft lead from being deformed in the handling, but I also think the rounded nose is a better design for bullets moving at .22LR speeds. Czech out the underwater shape of ship hull designs, for example. They aren't long and pointy... they are deliberately made rounded, almost blunt, because that is the best shape for moving through water at the speeds they move. I'm guessing the same is true with sub-sonic (or nearly so) bullets moving through air.

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Old 06-05-2010, 06:35 PM
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Originally Posted by Sophia View Post
I suppose it would be hard to keep a long thin point of soft lead from being deformed in the handling, but I also think the rounded nose is a better design for bullets moving at .22LR speeds. Czech out the underwater shape of ship hull designs, for example. They aren't long and pointy... they are deliberately made rounded, almost blunt, because that is the best shape for moving through water at the speeds they move. I'm guessing the same is true with sub-sonic (or nearly so) bullets moving through air.

That must be the WM Federal Bulk ammo container ship
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  #7  
Old 06-05-2010, 07:00 PM
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Why the dimpled nose of some very pricey match .22 RF ammo? It seems unlikely this'd be some kind of manufacturing aid, or it'd probably show up on bulk pack stuff. Since it's not on hunting ammo it seems equally unlikely to be for improved terminal ballistics. But I'm double-dambed if I can see any accuracy or windage advantage either.

What am I missing
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Old 06-05-2010, 11:53 PM
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Bullet BC is calculated by bullet shape, weight, and velocity it is pushed as well as a few other factors.

The main reason the 22LR has a round nose it is a multi purpose round. It was engineered for rifles and pistols of many types. Also as mentioned before the case that the bullet is seated in is equal to the bullets diameter. The average velocity generated out of a 22LR cartridge is below the speed of sound(1100FPS) and the greatest ballistic gain would be with the use of a round nose.
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Old 06-07-2010, 08:18 AM
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Thanks for the replies

Thanks for the replies, I am learning much...
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Old 06-07-2010, 05:26 PM
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Thanks for the replies, I am learning much...
No problem thats why were here.
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  #11  
Old 06-10-2010, 06:10 PM
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Palmetto, a short answer to your question is only guaranteed to provoke still more questions. Bullet design is one of those fields where most every aspect is the product of a long series of compromises. It's usually a matter of picking from among the best of the available options or, in some cases, the least worst options. That means there's usually not one complete answer to such a specific question but rather a bunch of partial answers that roll up together to make one (sorta) complete answer.

To cut to the chase, most bullets in widespread use were designed to work best in one of three realms of flight: either subsonic, supersonic or transonic (which runs from roughly 0.8 to 1.2 times the speed of sound). Just as is the case with airplanes, you pretty much can look at a bullet and tell which of those three realms is it was designed for (except that no one ever designed a transonic airplane because even the jet jocks don't spend any more time there than they have to).

That, in a nutshell, is why .22s tend to have round noses and .17s have points. It's because the .22 spends much of its flight time at transonic velocities but the .17 spends most of its flight time supersonic.

I've been trying too long already to write a simple explanation of what one has to do with the other but suffice to say that pointy bullets don't work well in the transonic realm. There are some phenomena that a pointy bullet thrives on that don't even show up for the party until the bullet is supersonic. Take those away and the pointy bullet's stability suffers, and the transonic realm is no place for a bullet to go wobbly.

Round-nosed bullets, OTOH, manage transonic speeds pretty well, although they're largely designed from a set of "least worst" compromises. Even .22 Magnum bullets -- which start out with an MV that is well supersonic -- generally only have an elliptical shape, which offers a bit more efficiency than round while they're supersonic without turning them into a whirling dervish by the time they've slowed to transonic.

Yes, pointy bullets do perform well at subsonic velocities in guns like the .300 Whisper but they don't offer any significant aerodynamic advantage over an elliptical or round-nosed bullet. Plus, they require a faster twist barrel than a more blunt bullet of the same weight.

Speaking of twist. one point I don't think was addressed was the rate of twist of a .22 versus a .17. A typical .22 has a twist of 1:16. A typical .17 HMR or .17 Mach2 has a twist of 1:9. The faster twist is necessary because 1) the smaller diameter bullet makes for less angular momentum at a given RPM so it needs more RPMs to make the same stability, and 2) the pointier and sleeker the nose of a bullet is, the less stable it generally is in flight. You have to spin the ever-lovin' crap out of high ogive number, low drag bullets (like Lapua Scenars) to make them stable.

Okay, I've had to restrain myself from going off on other multiple tangents, so I'm stopping now. This could turn into a full-blown 20-page discussion but I think I hear a six-pack calling my name.

...Drink me! ....DRINK ME!!!!!! ....


If you're interested, this is a pretty good online reference source for most stuff to do with external ballistics (in the broader sense).
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Old 06-11-2010, 06:26 AM
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What we haven't gotten to yet is that the shape of the heel of the bullet matters more @ .22 LR velocities.
Everyone has that round that catches on the feed ramp and deforms the bullet. I shoot it anyway, and you can sometimes see it "fly" outside the group, but sometimes not.
If you have a bolt action .22, try deliberately deforming the ogive section (forward of the driving bands) of a few rounds, and shooting a 50 yard group with them. As long as you don't remove any material, it all flies and balances much the same.
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Old 06-14-2010, 06:28 PM
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Quote:
Originally Posted by Tennessee Slim View Post
Palmetto, a short answer to your question is only guaranteed to provoke still more questions. Bullet design is one of those fields where most every aspect is the product of a long series of compromises. It's usually a matter of picking from among the best of the available options or, in some cases, the least worst options. That means there's usually not one complete answer to such a specific question but rather a bunch of partial answers that roll up together to make one (sorta) complete answer.

To cut to the chase, most bullets in widespread use were designed to work best in one of three realms of flight: either subsonic, supersonic or transonic (which runs from roughly 0.8 to 1.2 times the speed of sound). Just as is the case with airplanes, you pretty much can look at a bullet and tell which of those three realms is it was designed for (except that no one ever designed a transonic airplane because even the jet jocks don't spend any more time there than they have to).

That, in a nutshell, is why .22s tend to have round noses and .17s have points. It's because the .22 spends much of its flight time at transonic velocities but the .17 spends most of its flight time supersonic.

I've been trying too long already to write a simple explanation of what one has to do with the other but suffice to say that pointy bullets don't work well in the transonic realm. There are some phenomena that a pointy bullet thrives on that don't even show up for the party until the bullet is supersonic. Take those away and the pointy bullet's stability suffers, and the transonic realm is no place for a bullet to go wobbly.

Round-nosed bullets, OTOH, manage transonic speeds pretty well, although they're largely designed from a set of "least worst" compromises. Even .22 Magnum bullets -- which start out with an MV that is well supersonic -- generally only have an elliptical shape, which offers a bit more efficiency than round while they're supersonic without turning them into a whirling dervish by the time they've slowed to transonic.

Yes, pointy bullets do perform well at subsonic velocities in guns like the .300 Whisper but they don't offer any significant aerodynamic advantage over an elliptical or round-nosed bullet. Plus, they require a faster twist barrel than a more blunt bullet of the same weight.

Speaking of twist. one point I don't think was addressed was the rate of twist of a .22 versus a .17. A typical .22 has a twist of 1:16. A typical .17 HMR or .17 Mach2 has a twist of 1:9. The faster twist is necessary because 1) the smaller diameter bullet makes for less angular momentum at a given RPM so it needs more RPMs to make the same stability, and 2) the pointier and sleeker the nose of a bullet is, the less stable it generally is in flight. You have to spin the ever-lovin' crap out of high ogive number, low drag bullets (like Lapua Scenars) to make them stable.

Okay, I've had to restrain myself from going off on other multiple tangents, so I'm stopping now. This could turn into a full-blown 20-page discussion but I think I hear a six-pack calling my name.

...Drink me! ....DRINK ME!!!!!! ....


If you're interested, this is a pretty good online reference source for most stuff to do with external ballistics (in the broader sense).
Twist rate has to do with two critical areas. One is bullet weight and length the other is velocity.

Usually a bullet with an elongated metplat(VLD and ULD bullets) has a higher BC(ballistic coefficient) than most but to stabilize the same bullet weight with the longer metplat the bullet must rotate slightly faster or must be shot faster out of that rifle.

The velocity of a 22LR and weight of its bullets that are commonly used are between 30-40gr. and the velocity is usually between 1030-1600fps. This means for the bullets in this catagory to be adequately stabilized in flight the rate of twist must be 1:16. Now on some odd weight bullets( Aguila 60gr SSS) the correct barrel twist should be 1:9 twist due to the low velocity and length of the bullet. Although some barrels with the standard twist rate are more forgiving and will stabilize this bullet.
Their are charts for this information on the Internet that are floating around I'm sure some one can find one.

The round nose is engineered for most of the flight in the trans. or subsonic area and the heel is for the bullet to be able to fit in the case since the dimensions of the bullet driving band and the case are nearly the same diameter. The heel does serve another purpose as well it expands when it is pushed down the barrel to help seal the burning powder behind it preventing the hot gases from going around the bullet and losing performance.

One has to think a 22LR cartridge was originally designed for guns using black powder, so it resembles a mini-ball and uses the old technology that has been proven. Like the old saying goes" if it ain't broke don't fix it."

Last edited by Vais01; 06-14-2010 at 06:32 PM.
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Old 10-25-2017, 06:26 PM
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Originally Posted by 22-Rimfire View Post
My guess is that a pointed lead 22 bullet would be too fragile and subject to damage. It would also likely create feeding issues in many 22 firearms. There is also the potential issue of rounds going off from tubular magazine rifles if the pointed bullets were used. Lever Revolution for 22 rimfires.
Old thread I know but there may be one or two still out there... I thought the chain fire concept was disproved for the most part by experiments deliberately trying to set them off in a lever gun to no avail. And that's a centerfire. Imagine how hard it would be trying to set off a .22 round in the tube ? Almost impossible logic would dictate. I do accept that feeding issues may occur in S/A's. Bolts may be pretty much immune from the feeding issues.

That aside, I did read most of the posts and the one that makes the most sense is the different twist rates in the barrels. Apparently someone COULD make a barrel that would accept a supersonic .22 round that would be accurate. But for now ( if I'm understanding this correctly ) is simply that the round nose is the most accurate in present day .22's. That's pretty simple to understand. Also explains why many find the slower rounds to be more accurate that the hopped up versions.

This was an interesting read. Thanks to whoever started it.
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Old 10-25-2017, 08:08 PM
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Probably like the wheel, Round worked much better than Square
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