Power/Ballistics/ Backyard...

[PAcanis]

I'm sorry if this is in the wrong spot. I didn't see a specific ammo or ballistics forum. And since all my posts have been here and my question relates to what I've been reading in this forum...

I've been reading a lot about jacking up the power on stock pellet rifles. And the term "backyard friendly" comes up a lot. Mostly with sound, but I've also read some posts referring to neighbors and the reduced range of airguns making it safer for use around neighbors.

So let's say you are pushing a pellet 900-1000FPS, which is only 200-100 FPS less than standard (subsonic) .22 rimfire ammo.
And let's say the pellet's weight is 18grs or above, which is 50% or greater the weight of your typical .22 rimfire bullet.
Why is it considered safer to shoot a pest with a pellet rifle over a .22 rimfire? What is it about a pellet's ballistic performance that causes over travel to be less of a concern? Is it the shuttlecock design of the pellet that causes it to lose velocity and fall that much quicker? If that does indeed happen. Rate of twist maybe?

[aluminumfetish]

22 lr subsonic is in the range of 40grains at 750-800 fps.

[anti-squirrel]

Unless shooting slugs or cast boolits, I think most people want their .22 pellet guns shooting under 930 FPS.  That seems to be where you hit the "within 10% of speed of sound" area (dependent on barometric pressure and altitude).  If a pellet goes trans-sonic, the shockwave causes problems with accuracy. 

For many people, I think shooting .22 pellets is preferred because they can be used where any powderburner cannot, such as many urban/suburban settings.  My neighborhood is a perfect example.  I also don't have to worry about over-penetration with a pellet whereas I would with a firearms.  Then there's cost as a factor- especially with regard to cost-per-shot.

Many people seek more power out of their airguns for hunting, but for poking holes in paper, more is not always better, unless you're talking efficiency and consistency.  A quick search will reveal many owners of higher-end springers will de-tune the power on their guns to shoot at or around 12 FPE.  And when it comes to PCPs, a longer and more consistent shot-string that makes more efficient use of the given air supply is often preferred over a few huge-power shots unless hunting.

I could get away with shooting subsonic .22LR in my backyard, and I have a neighbor that has shot CB caps at pests in the past, but after he saw how his bullets zip right through a squirrel without killing it where my Benji 392 and PP700W pistol (in .177!) will stop a squirrel dead in its tracks, he is no longer using his .22LR rifle for pesting. 

There are many factors when it comes to choosing a firearm versus a pellet gun for making shots.  Mine are based off what I can legally use in my yard for pests and the concern regarding over-penetration and thus striking something unintended in the background.  The shuttle-cock design is another factor.  Pellets have more drag, thus they slow down faster.  For me, it is a clear and easy choice, especially since I have several .177 (even lighter and less energy) airguns that can be used effectively for pesting and hunting.

[PAcanis]

22 lr subsonic is in the range of 40grains at 750-800 fps.

Perhaps you are thinking of CB caps?
Anything below the speed of sound is considered subsonic. At least we tend to call it subsonic, when really it used to be known as standard velocity and anything faster was HV.high velocity.
90% of the .22 rimfire I shoot (Wolf MT, Eley red box, Aguila target) is subsonic and  it is much faster than 750-800FPS, approaching 1100FPS.

While that wasn't really what I was asking, it brings up an even bigger disparity over which has more power, your 900FPS pellet rifle or your 750FPS .22.

[PAcanis]

Thanks Anti-Squirrel. That's what I was looking for.
I hadn't even considered the over penetration of the pest itself. Very valid point. As was a pellet having more drag.

Thanks.

[balllistic]

Backyard friendly is subjective as it relates to noise and power levels (FPE), there is no rule of thumb as everyone's situation is different.

Even the quietest air rifle at low power would be irresponsible to shoot in a yard if the backstop is inadequate or unsafe. The same safety rules apply to airguns as they do to powderburners: Always know what's beyond your target. Increasing the power means an increased risk of stray/deflected rounds or penetrating shots to quarry carrying enough energy to do damage to property or cause serious bodily injury or death..

[PAcanis]

Backyard friendly is subjective as it relates to noise and power levels (FPE), there is no rule of thumb as everyone's situation is different.

Even the quietest air rifle at low power would be irresponsible to shoot in a yard if the backstop is inadequate or unsafe. The same safety rules apply to airguns as they do to powderburners: Always know what's beyond your target. Increasing the power means an increased risk of stray/deflected rounds or penetrating shots to quarry carrying enough energy to do damage to property or cause serious bodily injury or death..

One can only hope everybody feels this way.

I'd like my air guns to shoot as accurately as they can, but I don't need them to shoot close to the power of a .22 rimfire.
If I can dial down the power for more shots per fill and the groupings don't increase, I'd be a happy camper.

[anti-squirrel]

While that wasn't really what I was asking, it brings up an even bigger disparity over which has more power, your 900FPS pellet rifle or your 750FPS .22.

This is actually pretty easy: straight-up foot-pounds (or Joules) of energy.

A physically more massive (heavier) projectile moving slower can carry a lot more energy.  Consider this, which is looking strictly at speed of projectile and weight:

18.6 grain pellet @ 930 FPS: 35.7 FPE
40 grain bullet @ 800 FPS: 56.8 FPE

And consider this: I had a 72-pound Howard Hill Big 5 longbow, at my 30" draw length it drew to 78#s with some oak "piles" (34" long arrows with bodkin points that weighed around 837 grains average) and shot at a sluggish 168 FPS, it produced 52.44 FPS.  While getting shot with either bullet or pellet wouldn't be fun, arrows from my Big-5 would ruin your day even using blunts.  Not an efficient bow, but it would knock the socks off whatever I hit despite the very slow projectile speed. 

A sling (not slingshot) is even more fearsome... Balearic slingers from the age of the Holy Roman Empire would hurl a 2 ounce weight (over 800 grains) at a speed of 200 FPS easily.  Typical projectile weight ranged from lightweight 1 ounce lead sling-bullets up to fired clay "stones" weighing a pound.  The 2-ounce weight at 200 FPs is just shy of 80 FPE.  In other words: Slower is not always less energy.  And is why I prefer a heavy projectile at lower speed over a faster lighter projectile.

[PAcanis]

I'm with you there, A-Squirrel.
I like heavier bullets in most of my handguns. 147gr in my 9mm's, 158 in the .357's (over the popular 125gr HV burner).
But I'm not a fan of lobbing bullets/pellets either if I want to shoot something at longer ranges. Not to pick up foot libs of energy that I may or may not need.
So far, in my Puncher Breaker anyway, the 15.89 seemed to shoot just a little better than the 18.13. So I may not need to worry about a trajectory that deviates very much when I start dialing it down. Sometimes light and fast is all you need.

[Smaug2]

but I've also read some posts referring to neighbors and the reduced range of airguns making it safer for use around neighbors.

Yes!

So let's say you are pushing a pellet 900-1000FPS, which is only 200-100 FPS less than standard (subsonic) .22 rimfire ammo.

FWIW: I usually go for around 850, as this is the most accurate range for diabolo pellet shapes.

And let's say the pellet's weight is 18grs or above, which is 50% or greater the weight of your typical .22 rimfire bullet.
Why is it considered safer to shoot a pest with a pellet rifle over a .22 rimfire?

You're assuming .22 caliber, it sounds like. I mostly stick with a .177 at between 12 and 20 FPE and it's more than enough, 90% of the time.  If the pest is a big one, like a raccoon or possum, I get out the .22 airgun at 20-35 FPE, but make darned sure I'm using the earth as a backstop. Even then, in case of a miss, if the ground is frozen and the shot is a shallow angle one, the pellet ricochets and continues on downrange with considerable energy. I had it happen once when I was shooting my Summit at a target stapled on an empty box in the winter.

But anyway, it's about the energy the pellet is still carrying after punching through the animal. For example, if you're shooting up at 45° at a squirrel with a .22 rimfire that's carrying 125 FPE, that bullet will often only dump 20 FPE or so into the squirrel. The other 100 FPE is still in the bullet, which will land God knows where. Break windows, hurt someone or something.

What is it about a pellet's ballistic performance that causes over travel to be less of a concern? Is it the shuttlecock design of the pellet that causes it to lose velocity and fall that much quicker? If that does indeed happen.

That's part of it too. So: less energy and less efficient pellet shape = safer for the typical backyard in case of a pass-through or miss.

[PAcanis]

Thanks for detailing that out, Smaug2.

Where do those poly tipped pellets come in? Are they designed to break up quicker upon contact with the ground, tree, rock?
I know poly tipped varmint loads, whether .223 centerfire or .17HMR rimfire, will break up rather quickly rather than ricocheting. And of course fragment and dump their energy when hitting what you are aiming at. I was surprised when you said a pellet will ricochet. I figured the lead was too soft.

This really has me questioning some of the videos I see on YT. And also what PA told me when I bought my first springer years ago.

[PAcanis]

I've got another question, which kind of relates to this thread. At the least I'll learn something.

Why does everyone seem to go by FPE?
I just read a thread from someone asking for a gun recommendation within a certain FPE. FPE is based on velocity AND weight of the projectile, isn't it? How can you recommend an airgun with a certain FPE if you don't know what pellet weight they will be shooting?

[pllagunos]

Due to the ballistic coefficient of a pellet such as a JSB heavy 18.1, which is 0.031, pellets lose their velocity and thus energy very quickly compared to firearms, the pellet shape is one of the reasons of the low BC. Then a standard .22 PCP shots something like 30 ft/lbs while your .22 subsonic shots 60 ft/lbs, also a pellet is cheaper and is generally more acceptable to be used in neighborhoods by the people living on it than say a .22 lr subsonic.

All this makes a pellet much safer to shot in urban/suburbs areas compared to a .22lr. At least that's how I view it.

[anti-squirrel]

I've got another question, which kind of relates to this thread. At the least I'll learn something.

Why does everyone seem to go by FPE?
I just read a thread from someone asking for a gun recommendation within a certain FPE. FPE is based on velocity AND weight of the projectile, isn't it? How can you recommend an airgun with a certain FPE if you don't know what pellet weight they will be shooting?

In general, I think people have a level of energy they want to hit.  Though there are some milestones or benchmarks, such as 40FPE with a .22 (or 50 FPE), hitting 100 FPE with a .25, or 20 FPE with .177. 

I like to shoot for accuracy and shot count, which means efficiency, but for people pursuing power, power, and more power, they are usually either going for a static goal as an achievement ... Or going for prey requiring a certain energy level. 

The UK shooters have done a lot to dispel myths about power levels.  Taking game at 40 and 50 yards with sub-12 FPE guns thanks to super-precise shot placement.  Plus 10-meter competition guns.  They don't need to be powerful, they need to be super accurate and super repeatable.  I think because of this, the focus we've seen on monster power has actually been detrimental, much like PBA ammo that goes supersonic to satisfy ridiculous projectile speed claims, yet offers less-than-stellar accuracy.

Otherwise, pellet weight is part of the energy equation, and I'd rather have accuracy over power- within reason, of course.  Energy commensurate with game.

[Doug Wall]

900-1000 fps with 18 grain pellets is well out of the range for many run of the mill guns. I just did a bunch of pellet testing using a Beeman Silver Kodiak X-2. This is a pretty hefty air rifle, just under the magnum class. It's advertised at 830 fps, with the .22 barrel. The only pellets that I could get to beat 830 fps, were the Crosman SSP (actual wt. was 8.73 gr). Power came out to about 16 FPE. The only pellets that I did that were close to 18 gr., were the Stoeger x magnums, at 17.34 gr. I was only getting about 625 fps. with these (15 FPE). With proper shot placement, 15 FPE will take most backyard pests, and that's much lower than the 100+ FPE for regular HV .22LR.

[PAcanis]

Thanks again for helping to bring me up to speed guys.

[Smaug2]

Thanks for detailing that out, Smaug2.

Where do those poly tipped pellets come in? Are they designed to break up quicker upon contact with the ground, tree, rock?

They're design to hit like a wadcutter and expand like a hollow point, and the tip just makes them a bit more aerodynamically efficient. (wadcutters and hollow points with big cavities are horrible, in this regard) They're still not as good as domed pellets downrange, but they're a lot better than they would be otherwise. The tips tend to break off almost immediately after entering an animal, but do give some initial penetration. The poly tips on PB rounds are also designed to push back and aid the bullet in expanding. The pellet tips don't do this.

Why does everyone seem to go by FPE?

It's the US unit for energy carried by projectiles. In other, more sensible countries, they use Joules, the standard SI unit of energy.

I just read a thread from someone asking for a gun recommendation within a certain FPE. FPE is based on velocity AND weight of the projectile, isn't it?

Yep. Energy = [(projectile mass in grains)(velocity in fps)(velocity in fps)]/450,435

How can you recommend an airgun with a certain FPE if you don't know what pellet weight they will be shooting?

It usually doesn't vary by a lot, since a given gun will shoot a heavier pellet slower than a lighter pellet. With pneumatic guns, it varies a bit more than with springers, since a heavier pellet will spend more time in the barrel, giving the pressure more time to push it harder. With springers, the compressed air is more localized and more instantaneous.

[39M]

I don't shoot pests in the yard. And all my targets have backstops.

Pellets either stick in the wood, nothing I shoot is powerful enough to go through at the ranges I put them. Some just flatten out and bounce back a few inches.

Or I have two steel plate backstops.
But still not going to shoot a pb.

Kind of a funny question to ask, I think.

[Ribbonstone]

Basically, a .22 RF (lets say a typical .22LR HV) will manage 92-100 foot pounds at 100yards.  That's a performance level that small bore airguns really can't match.

40gr. .22LR slug has a BC (BC being an estimation of how well a projectile holds onto velocity) of something between .11 and .12.  Pellets more likely to be between .02 and .04 (basically 4 to 5 times WORSE at holding on to their initial speed).  Pellets do start slower, slow down faster, and that limits their down range danger ("limits" but not remove).

[PAcanis]

Thanks for the lowdown on the poly tipped, Smaug2.

Thanks, Ribbon. Looks like I grossly overlooked the BC