Discussion in 'Airguns' started by saturno_v, Nov 25, 2013.
As for stability, there's nothing says an airgun has to shoot a "pellet." Some air rifles are powerful enough to shoot rotationally stabilized solid pellets or even real bullets (eg 125 gr 357 bullets).
Never try to shoot a bullet out of an air rifle. Too many variables (first, no firing pin ... 2nd, barrel is not meant for firearm ammo ... I could go on, but I won't) to go wrong.
fps has nothing to do with accuracy or effective knock down power. Lightweight plastic pellets will hit blazing fast speeds - enough to break Mach-1 and you'll hear the same crack of a firearm, but no popwer at the receivng end because of the low weight of the pellet. Also, after a certain distance, the light weight pellets capable of achieving these muzzle velocities do not have sufficient "oomph" to stay on course and drop down or can be blown off course by a breeze.
There are plenty of conversion tables on the web that will give you the combination of pellet weight and muzzle velocity needed at a specific distance (key here) to provide the force needed at the target (penetration) with accuracy.
I think you misunderstood
Craftsman i think you misunderstood the previous post. There are several large bore air rifles that due in deed fire lead bullets. Not the whole cartridge, just the lead bullet. If you are unfamiliar look up the DAQ Dennis A Quakenbush rifles. They truly are a work of art.
I guess I did. Thanks.
EDIT: THIS IS THE BEST .22 CALIBER PELLET PICTURE DATABASE I've ever seen. There's also a .177 caliber database on the same forum.
I have an idea that I don't think has been utilized: use a a really heavy spring and compressing piston, and fairly large compression chamber, but use a ratchet system, so that each stroke of the lever compresses the spring, say, 10% (assuming a linear compression spring) It might take ten 'pumps' to fully compress the spring, but you could get some serious velocity from the resulting 'slam' compression! Of course you'd be supersonic with the resulting 'crack'.
They've made some pretty crazy air guns to simulate small scale crater impacts in space that have gotten up to 6000 m/s! Of course the things take a building to house.
The way to get truly crazy speeds out of an air gun would be higher pressures and longer barrels in a PCP gun. For the most part no one bothers with that, because given a certain amount of air out of the valve, you can get higher FPE with a larger and thus, slower, projectile.
I have a .45 Cal PCP air rifle and I use the same bullets that I shoot in my 1911. Just the bullets.
Highest I've found ... 1,650 fps
http://www.pyramydair.com/s/m/Gamo_Hunter_Extreme_SE_Air_Rifle/3236#Specifications Gamo Hunter Extreme .177 $440 Breakbarrel.
Just a note, if you read the review on Pyramyd Air by Tom Gaylord, (in the blog) he gets a maximum velocity of closer to 1350 with the PBA pellets.
As for realistic store bought stuff you're probably looking at closer to 1500fps as a max using useless super light pellets. My Benjamin Titan for example can hit 1290 with a 5.2gr pellet, corrected to sea level it would break 1300, and that's not even a magnum, just a standard $90 gun.
For realistic usage everyone stays under the speed of sound. Most guns are stuck there anyway, but if you break it you lose accuracy and noise goes way up so there's no point. Super accurate air guns usually stick to 500-550fps, guns for hunting are usually more accurate at 900fps or less, but it varies on the gun. No point in having a magnum hunting gun and tuning down to 550 for accuracy, but if an 18gr pellet shoots at 850 and a 14gr shoots at 950, chances are the 18 will be better all around for a variety of reasons including the weight and BC.
So I guess it all depends on what you mean by practical. I have several that shoot .177 at 1000 to 1050 and they're fine for hunting, but using a heavier pellet to bring then down to 850 is probably better for most applications as long as the gun likes the pellet. Airguns, especially springers can be finicky so what works on most might not work on your gun so not just velocity and weight, but the make/model of pellet is a factor too. The best thing is to try as many different pellets as you can to see what works for you and yours. I even saw a website once that has a pellet exchange program where people exchange small numbers of pellets rather than waste $10-20 per tin. I usually stick to JSB and H&N pellets, but RWS and Crosman Premier are also good. If your gun can't shoot any of those then chances are there's a problem that needs to be fixed before you can continue.
So basically ~550 for max accuracy, ~900 for max hunting accuracy, and supersonic for max period unless you're just goofing off.
Hope this helps
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