How fast is too fast?

contaucreek

contaucreek

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I am tossing around the idea of a spring action airgun for pest and small game. I have no idea if I should go .177 or .22 but I see that certain rifles (Diana) come in velocity options.
Is there a big advantage to 800+fps or do bad things start to happen to pellets driven at high speed in terms of accuracy?
I understand that striking energy is higher but does it come at a price?
Does a 495fps rifle have it takes to harvest the small stuff or would a a PAL class rifle be what I want?
 
While I’m not going to argue the usefulness of a sub 500fps air rifle/pistol, if you’re going to go pal, a .22 short will have more power and possibly be quieter. A pal rated air rifle just isn’t worth it IMO because it’s treated the same as a 50 BMG.
 
contaucreek said:
I am tossing around the idea of a spring action airgun for pest and small game. I have no idea if I should go .177 or .22 but I see that certain rifles (Diana) come in velocity options.
Is there a big advantage to 800+fps or do bad things start to happen to pellets driven at high speed in terms of accuracy?
I understand that striking energy is higher but does it come at a price?
Does a 495fps rifle have it takes to harvest the small stuff or would a a PAL class rifle be what I want?
Click to expand...

It's when you start getting over 1000 FPS is when accuracy seems to suffer, most people I know that hunts with airguns uses .22. 177 be good for squirrels and small birds. But you can get heavier pellets to lower the FPS but increase the FPE.
 
What specifically do you plan to hunt ? Stick to over 495. Either cal n general, each have their fan clubs, own and use both. Advantage is ammo price compared to shorts. Velocity on product box generally inflated.
 
In my experience(experimenting), I saw diminishing accuracy results after around 880fps. That was with one PCP rifle with one known accurate pellet. So not saying its the be all end all, just what I found.

Airguns are just a different branch of the shooting sports and I have as much enjoyment from it as I do my powder burning hobby. I wouldn't tell a guy who enjoys muzzle loading that he should just use a .308. Lol
 
First you will need to find a pellet the rifle likes. For a springer in .177 you can shoot 8gr up to about 10grain. In 22 you can shoot 14 grain up to about 18grain. Some companies sell sampler kits so you can find which pellet your rifle likes.
For hunting, I find 22 is best.
Breaking the sound barrier can cause a lighter pellet to tumble. Even a heavy pellet that is not designed for high speed.
For myself, I try to stay under the speed of sound when hunting small game just to avoid the crack of the sonic boom. There is enough wallop delivered even with a cheap Crosman 14.3 grain pellet flying about 750 FPS. That would be around 17 ft-lbs which is pretty good.
Shot placement is key. I have sub 500 fps shooters in 22 I use for hunting too.
For a sense of ease, after the hunt, the rifle needs very little cleaning. No gun powder residue left is the barrel.
Shooting a full power or magnum springer does take practice to achieve accuracy. They like to be held consistently.
Lastly, don’t trust manufacturers FPS ratings, check reviews first
Cheers,
 
A pellet will experience turbulence which will destabilize it when it crosses the sound barrier, so subsonic velocities will generally be more accurate. A high-velocity pellet, even if it starts out at supersonic velocity, will drop below the speed of sound very quickly, and again experience that same destabilization. So unless the supersonic gun is so powerful that the pellet remains supersonic (i.e. in excess of about 1100fps) all the way to the target, you are almost guaranteed to experience degraded accuracy.

It's the same idea as the ultra-long-range centerfire target shooters, who want their bullets to remain supersonic out to the farthest range at which they will be used.
 
The problem with pellets going too fast is that they destabilize in flight rather easily when the approach transonic speed. That is to say pellets experience turbulence when nearing and leaving the speed of sound. As Mulby says, it varies with pellets and rifles, but the winnowed wisdom is that over 900 - 950 fps is where problems occur. The lighter the pellet the greater the impact on loss of accuracy.

And it's not just approaching the speed of sound that causes instability in the pellet's flight. Slowing down from the speed of sound causes similar instability. Pellets are like badminton birdies in that they slow down very quickly compared to powder propelled bullets. Pellets have a low sectional density and a low ballistic coefficient. A pellet that exceeds the speed of sound may travel without instability but it will quickly slow down to below the speed of sound and will experience transonic turbulence.

Edit: jjohnwm posted as I was typing.
 
Heavier pellets won't nessisarily save you from instability. It's the traditional shape of -head, waist, and skirt that cause disturbance during sonic stages. The pellet as we know it was essentially designed to be shot bellow trans-sonic ranges. Slugs or cylindrical would be less affected.
The idea of heavier pellets being less affected is generally brought from guns that are powerful enough to break the sonic ranges with average weight pellets being slowed enough to keep things at a speed that works in those guns.
 
Threemorewishes said:
Use heavy pellets and breaking the sound barrier won't be an issue.
Click to expand...

It can very well remain an issue, especially at increasing distances shot. The problem is also seen in high velocity .22LR ammo when longer distances such as 100 yards are being shot. HV ammo starts off over the speed of sound but by 100 yards is below. That is one of the key reasons that it is less accurate than standard velocity ammo, which never exceeds the speed of sound.
 
Smcx said:
While I’m not going to argue the usefulness of a sub 500fps air rifle/pistol, if you’re going to go pal, a .22 short will have more power and possibly be quieter. A pal rated air rifle just isn’t worth it IMO because it’s treated the same as a 50 BMG.
Click to expand...

Someone once said ... a little knowledge is a dangerous thing
 
It is well known on the CAF that anypellet regardless of what caliber unr using will have issues with accuracy usually beyond 950fps. I find best accuracy with almost all mine between 925-950fps. If using for hunting I would not go less than 700 FPS with a 22. The larger the caliber at the 925-950fps range the better in the wind and extra fpe.
Even though my 25 cal condor can push a 24gr pellet to 1200fps its more accurate and hits harder with a 40gr pellet at 925fps.
There is so much to know and learn about airguns that it is a whole different shooting sport in itself
 
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