Very light pellets at very high speed?
- Thread starter MrP
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This thread started to discuss light pellets at high speed and evolved to slugs as well.
My PCP is tuned for H&N Baracuda 18. Previously I tried slugs and had the regulator pressure much higher and tested with JSB 13 grain and it reached speeds of about 1140fps. The efficiency was not good as the pellet's muzzle energy was much lower than with slugs, and I assume the valve was still open by the time the pellet left the muzzle. At 50 meter the accuracy was not to bad but with some flyers. As the rifle is now tuned for 18gr pellets at 36 FPE I tried again with the 13gr pellets and the speed was around 1020fps and 31 FPE. Accuracy was now worse than with the higher speed. I am not really interested to shoot as this higher speeds and this was just to test.
The flyers was the 1st and second shot which was a bit slower and the rest and higher speed shots grouped together.
Here is 5 shots I did today after seeing this thread, the first reading on the chrono was a shot into the grass just to check the speed.
I did read somewhere on the HAM site about air rifles getting it's best accuracy with some light pellets at supersonic speeds, but that is the exception and at short distance.
My PCP is tuned for H&N Baracuda 18. Previously I tried slugs and had the regulator pressure much higher and tested with JSB 13 grain and it reached speeds of about 1140fps. The efficiency was not good as the pellet's muzzle energy was much lower than with slugs, and I assume the valve was still open by the time the pellet left the muzzle. At 50 meter the accuracy was not to bad but with some flyers. As the rifle is now tuned for 18gr pellets at 36 FPE I tried again with the 13gr pellets and the speed was around 1020fps and 31 FPE. Accuracy was now worse than with the higher speed. I am not really interested to shoot as this higher speeds and this was just to test.
The flyers was the 1st and second shot which was a bit slower and the rest and higher speed shots grouped together.
Here is 5 shots I did today after seeing this thread, the first reading on the chrono was a shot into the grass just to check the speed.
I did read somewhere on the HAM site about air rifles getting it's best accuracy with some light pellets at supersonic speeds, but that is the exception and at short distance.
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Didnt read through all the comments...
Per the title...realized an interesting fact about pellets when shooting over a friends Labradar one time...whether they left the barrel at 980 or 915, they were going about the same speed by the time they got to 50 yards. This was with a relatively hith BC pellet (0.048). This effect would only be amplified as the BC comes down to typical pellet BCs. That little experience showed me that there's no point in pushing them faster if the speed is the same at as close as 50 yards like that.
In short, for most pellets, pushing them super fast just wastes air. They're going to strip their speed FAST, in most cases.
Per the title...realized an interesting fact about pellets when shooting over a friends Labradar one time...whether they left the barrel at 980 or 915, they were going about the same speed by the time they got to 50 yards. This was with a relatively hith BC pellet (0.048). This effect would only be amplified as the BC comes down to typical pellet BCs. That little experience showed me that there's no point in pushing them faster if the speed is the same at as close as 50 yards like that.
In short, for most pellets, pushing them super fast just wastes air. They're going to strip their speed FAST, in most cases.
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I have no way to measure speed at distance so I rely on balistic apps and other people like you who did the measurements. Although with different pellets and at different conditions the results should be similar.
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E=mc2. It means that mass and energy are related and can be changed from one to the other. Mass is basically the amount of material an object contains (which is distinguished from weight, which is the force of gravity on an object). Einstein thought it did. A projectile leaving the barrel hits a velocity pushed by the volume of air under pressure the mass of the air pushes against the mass of the projectile. When it leaves the barrel the force of gravity acting upon it creates once it leaves the barrel prevents it from continuing to accelerate among other factors like wind resistance. Or the force the air applies to the projectile. It hits a velocity that is stable and equal to the mass or volume of air that was released under pressure. According to newton every action has an equal and opposite reaction. Therefore mass energy and force are all equal reactions to various conditions either produced from the mass of the object, the volume of air under pressure or the environment. I believe all of theses are ruled by the laws conservation of energy except the gravity one that would be the newton’s universal law of gravity. But even then gravity is dictated by mass and the amount of energy created by a mass and the energy it creates is still bound but the law of conservation of energy. Because a mass or energy source can only produce energy equal to its mass weather it’s air a projectile gas or a log burning on a fire.
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One thing I’ve noticed is when a valve is open when the projectile leaves the barrel is it screws with accuracy and in some cases slows the projectile down and reduces the fpe. When my element max was dumping air. The slug bounced off of the dell computer towers I was shooting. When it was fixed it hammered them.
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I can think that it must be the case as the air is then blowing all around the pellet.
But, I am just asking as I am no expert, how is it working with BP revolvers and pistols and carbine rifles? Even full length rifles where some the max SAMI pressure is up to 4,400 bar / 65,000 psi but with most loads well below that. There is still a lot of compressed air around the bullet after leaving the barrel. It must be different with bullets than for pellets. Slugs? Slugs are more like a bullet than a pellet. Some expert might be able to answer this. I know that bullets with the correct spin rate do some self stabilising in flight and the wobbling "goes to sleep", so that might be the saving from the un-stabilising from the muzzle blast. Again - Slugs?
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Maybe it’s not the weight that’s important, more the shape and CofG.
the reason being while testing different brands of pellets through my .20 I found that crossman premier at 14.3 gun fly like a laser at 1150fps while other similar weight or slightly heavier were like a frisbee at anything over 950fps.
Just a thought
Bb
the reason being while testing different brands of pellets through my .20 I found that crossman premier at 14.3 gun fly like a laser at 1150fps while other similar weight or slightly heavier were like a frisbee at anything over 950fps.Just a thought
Bb
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I remember I saw this some years back but could not remember where, now I found it. They don't say what the speed was but the impact is quite impressive.
There is another video I saw, testing the accuracy at 50y if I remember correctly, but will still find that. Accuracy was not good.
There is another video I saw, testing the accuracy at 50y if I remember correctly, but will still find that. Accuracy was not good.
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