fastest velosity

[yakfish]

what is the fastest velosity airgun you have seen? I found one made by Gamo.The Hunter 1250 Hurricane it shoot at 1250 fps. any out there that are faster than that?

[Talontsi96]

The Codor shoots a .22 caliber pelets at 1250 to 1300 fps. Way more energy there than the Gamo in .177.

here is alink:

http://www.gundepot.net/catalog.php?typ ... t&id=38089

[ABshooter]

Yakfish, one thing you should know about high velocity airguns, is that pellets are unsteady at a speed past 1050 fps.

[Talontsi96]

Another thing is they brake the sound barrier, therefore sounding like a .22 LR...Shot.

[yakfish]

thanks for the replies. I have a couple other questions too. what would make a pellet unstable past 1050fps? I would have thought that would only make it more accuate? also what is the speed of sound? I think I rememner it being around 650 miles/hour I can convert that to fps but am not sure if that is right or not.
I have been shooting an air gun for years but it is getting old and not nearly as powerfull or as accurate as it used to be. I have always been the kind that enjoys plinking cans but have never gotten into the technical side of the numbers.
Thanks for your help. these are some elementry questions but we have to learn somehow.
great forum here

[under500fps]

Here are some basic information just in case you did not have a chance to look at it before:

http://web.newsguy.com/geesaman/Airguns1.htm

www.airguninfo.com

[sniper]

Gamo Hunter 1250 is exaggerating on the fps advertised, you got to find
a very light pellet to achieve that on it.

I would say the Condor, B50/51, HW100 full power.

[TCooper]

Most Olympic style 10m target air rifles shoot around 570-600fps. Many shooters find the mild HW30S (R7) to be a very accurate air rifle out to 40 yards (600fps). More power doesn't always mean more accuracy.

There will come a point when the pressure could blow the pellet skirt when exiting the barrel. Pellets were not designed to compete with rimfire rifles (.17/.22). Anyone in love with velocity might want to consider .17 HMR rimfire or .17 centerfire cartidges. Airgunning is a relatively low velocity sport.

Todd

[thudthumper]

what would make a pellet unstable past 1050fps? I would have thought that would only make it more accuate? also what is the speed of sound? I think I rememner it being around 650 miles/hour

i'm going to actually try and answer all this, so it might get a bit lengthy...
i'll start here:

also what is the speed of sound? I think I rememner it being around 650 miles/hour

the speed of sound at sea level is right at 761.21 miles/hour. if you are located above sea level, the speed of sound could very well be 650 miles/hour for you since the air is less dense.

if you convert these numbers to feet/second:

(761.21 mi/h)*(h/60min)*(min/60 s)*(5280 ft/mi) = 1116.44 ft/s

i did the same for your estimate, 650 mi/hr and got 953.33 ft/s.

what's this mean? well, depending on your elevation the speed of sound probably falls between those two numbers...but it's probably closer to the lower end.


now that we can atleast estimate the sound barrier we can look at your other questions.

what would make a pellet unstable past 1050fps? I would have thought that would only make it more accuate?

pellets aren't shaped like their super-sonic bretheren, rifle bullets. bullets are streamlined to cut down on drag, whereas the principle behind pellets is the exact opposite. pellets have a tail that serves two purposes: 1) it cups the expanding air to accelerate the pellet down the barrel and 2) the tail, or skirt, induces drag to help keep the pellet oriented correctly downrange. a pellet actually works very similarly to a badminton birdie. this is desired at low speeds because the rifling in air guns is not as effective as rifling in powder burners. the projectile must spin about its longitudinal axis at a certain angular rotation in order to be properly stabilized. this just isn't possible due to the low velocities of an airgun, so the tail makes up for it.

so what? well, the sound barrier is in fact a physical barrier. as an object approaches the speed of sound, it is compressing the air in front of it. this pressure gets greater and greater, until the object (if it continues to accelerate) finally punches through this high pressure zone resulting in a loud pop, or sonic boom. this is why rifles are so much louder than most air guns.

when a pellet, which is designed to drag, begins to compress the air in front of it strange things happen. it often destabilizes and can tumble a bit, destroying its trajectory. a tumbling pellet wags its tail behind it, inducing drag in random directions. obviously, there is no way to predict exactly what will happen. in contrast, a rifle bullet is designed to slice through the air. it divides the high pressure zone much easier than a pellet, and passes through the sound barrier with very little effort.

often times you don't even need to break the sound barrier to throw off accuracy with pellets. as mentioned before, the faster an object is traveling, the higher the pressure zone in front of it. so, the faster a pellet is traveling, the greater the chance that it may destabalize ever so slightly. when you're dealing with aerodynamics, it doesn't take much to throw of a shot by a great deal. most competition shooters refuse to even approach the 900 ft/s mark for this reason.

i could go on and on, but i hope this is enough to make sense for everyone. i'll be happy to comment more if asked, but i'll otherwise leave it here. if anyone believes any of this to be incorrect, please speak up. i'm writing this off the top of my head, and the only thing i referenced was the speed of sound.

[Tailgunner]

What Thudthumper said.......... beat me to it and said it better. Thanks - great article.

Cheers - Gus

[thudthumper]

What Thudthumper said.......... beat me to it and said it better. Thanks - great article.

thank you

[jezX]

i have seen guns that will go 1400f/s , this is usless . at 1300 f/s i have had 14gr pellets spin to there death about 30 feet in front of me . any gun that shoots 1100+ f/s with 14gr pellets will have to use 20- 30 gr pellets to be accurate and that means the speed will be about 900f/s .so speed does'nt realy matter .
speeking of speed / power , did anyone notice that in the last nra magazine the talon was discused and the stats were messed up, 1100f/s with a 14.5 gr pellet = 7fp. this is the second time this year i have seen fd^ stuff. (i mean last year)

[Zonker]

I believe the difference in noise between an air rifle and a true firearm is mostly due to the discharge of the cartridge itself. If you take a sub-sonic pistol cartridge like a .45 ACP or some .357 Mag loads, they're many times louder than an air rifle, but they're velocities are still under the sound barrier (firing .357 Mag sans ear protection is something you'll probably only do once ). In the case of a high power rifle, the bullet has already broken the sound barrier long before is even leaves the muzzle.

Although technically a bullet does produce a "sonic boom", it's more like a "sonic pop" because the size of the projectile is so small.

Zonker

[thudthumper]

I believe the difference in noise between an air rifle and a true firearm is mostly due to the discharge of the cartridge itself

yes, and no if i remember correctly. both airguns and powder-burners use the exact same propellant if you get down to it--expanding gas. yes, there is a greater volume of gas generated from self-contained cartridges and that would yield a louder noise...but the sharp crack is the projectile breaking the sound barrier. a sub-sonic round should sound more like a wine bottle being uncorked.

and i'm not familiar with those pistol cartridges, so i'm afraid i can't comment on them at this time. i do know that even a .22lr goes super-sonic, so i would think that a .357 mag would as well.

In the case of a high power rifle, the bullet has already broken the sound barrier long before is even leaves the muzzle.

in the case of ANY firearm that goes supersonic, the bullet breaks the sound barrier before it leaves the muzzle. a bullet can only accelerate while it has a force acting behind it. as soon as it leaves the barrel, it begins to slow down because the only force acting on it at that point is drag from air resistance. this hold true for any projectile that has no thrust capabiliy.

Although technically a bullet does produce a "sonic boom", it's more like a "sonic pop" because the size of the projectile is so small.

yeah, it does make more sense calling it a "pop", but i doubt most people would. the magnitude of a sonic boom is directly proportional to the cross sectional area of the object passing through the wave front. basically, the bigger the object, the bigger the boom. no argument there.

i would like to add, though, that the US military (and quite possibly others) uses special sub-sonic ammunition for rifles that are to be "silenced." a silencer in reality does more to mask the muzzle-flash than to quiet the gun, so the cartridge must not make much noise to begin with. an unsuppressed sub-sonic cartridge (from what i've read) is generally much quieter than a standard super-sonic one.

zonker, i don't want to sound arrogant and i'm not trying to snuff everything that you send my way. i love discussing this stuff, and i hope you send more my way. also, i'm no expert on the issue--everything i've written is true to my knowledge, but i could be wrong. i haven't the time to try and cite this stuff.

[thudthumper]

here's a link that backs up my comments on attempting to silence super-sonic projectiles.

http://people.howstuffworks.com/question112.htm

ah, i'll just post what it says here:

Several alert readers have written to point out that a bullet that travels at supersonic speeds cannot be silenced because the bullet creates its own little sonic boom as it travels.