PCP guns
Moderators: pilkguns, m1963, David Levene, Spencer, Richard H
Pre Charged Pneumatic.
The gun is charged with compressed air, usually from a SCUBA tank but sometimes with a hand pump that looks like a bike tire pump. These accessories are added above the price of the gun.
Usually these guns are more powerful than most except match target guns where accuracy is the primary consideration or power is limited by the rules.
The gun is charged with compressed air, usually from a SCUBA tank but sometimes with a hand pump that looks like a bike tire pump. These accessories are added above the price of the gun.
Usually these guns are more powerful than most except match target guns where accuracy is the primary consideration or power is limited by the rules.
As Rover says, the gun has an air tank, usually rated to 200-300bar.
Most guns for ISSF style target shooting will not be set up for more than a muzzle energy of 6 foot-pounds, so will give well in excess of 60 shots per fill. Obviously if you were using one for hunting and tuned the power up, you would get fewer shots. Some are better suited to high-power usage than others due to the capacity of their tanks, and the pressure rating.
They're a bit of a faff for someone used to springers and single-stroke-pneumatics (SSPs), and are generally at the more expensive end of air guns (and having bought them, you then need a dive cylinder, or a pump, or a compressor, and obviously they need to be specialist kit - your average car tyre pump designed for 30PSI ain't gonna cut it when you need a 200bar charge).
However, the advantages are obvious. Compared to springers, there is no recoil, as no spring is whanging pistons around, and you needn't cock/pump it for every shot, meaning if the unthinkable happened and you winged your target when hunting, you could take a follow-up shot much more quickly.
In competition (say, an ISSF 40/60 shot match), there are clear advantages in that you do not have to work a cocking lever 40-60 times in a match. This means you can stay in position between shots, and also do not get tired from the effort of repeatedly cocking the gun.
The system is comparable to the CO2 airguns, but as the CO2 guns usually take quite small CO2 canisters, which are charged to a lower pressure, the number of shots you get is relatively small. And obviously CO2 canisters are disposable, whereas your expensive PCP cylinder is designed to be recharged.
Most guns for ISSF style target shooting will not be set up for more than a muzzle energy of 6 foot-pounds, so will give well in excess of 60 shots per fill. Obviously if you were using one for hunting and tuned the power up, you would get fewer shots. Some are better suited to high-power usage than others due to the capacity of their tanks, and the pressure rating.
They're a bit of a faff for someone used to springers and single-stroke-pneumatics (SSPs), and are generally at the more expensive end of air guns (and having bought them, you then need a dive cylinder, or a pump, or a compressor, and obviously they need to be specialist kit - your average car tyre pump designed for 30PSI ain't gonna cut it when you need a 200bar charge).
However, the advantages are obvious. Compared to springers, there is no recoil, as no spring is whanging pistons around, and you needn't cock/pump it for every shot, meaning if the unthinkable happened and you winged your target when hunting, you could take a follow-up shot much more quickly.
In competition (say, an ISSF 40/60 shot match), there are clear advantages in that you do not have to work a cocking lever 40-60 times in a match. This means you can stay in position between shots, and also do not get tired from the effort of repeatedly cocking the gun.
The system is comparable to the CO2 airguns, but as the CO2 guns usually take quite small CO2 canisters, which are charged to a lower pressure, the number of shots you get is relatively small. And obviously CO2 canisters are disposable, whereas your expensive PCP cylinder is designed to be recharged.
OK, by "CO2 guns" I meant those with the disposable canisters that Oz highlighted, which gives you the 4 main types of air gun:
- Springers
- Single Stroke Pneumatic (SSP)
- Disposable canister (invariably containing CO2)
- Pre-Charged Pneumatic (PCP)
If you want to put CO2 in a PCP instead of air that's fine! Out of interest why? I can't imagine it's any cheaper to source CO2 than standard air (unless you work in a lab with CO2 on tap!).
Getting CO2 refills is surely a relatively specialist affair, whereas refills with dry, breathing-quality air can be obtained from any good dive-shop or gun shop.
- Springers
- Single Stroke Pneumatic (SSP)
- Disposable canister (invariably containing CO2)
- Pre-Charged Pneumatic (PCP)
If you want to put CO2 in a PCP instead of air that's fine! Out of interest why? I can't imagine it's any cheaper to source CO2 than standard air (unless you work in a lab with CO2 on tap!).
Getting CO2 refills is surely a relatively specialist affair, whereas refills with dry, breathing-quality air can be obtained from any good dive-shop or gun shop.
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David Levene
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You have left a 5th type off your list. CO2 guns with refillable cylinders.Hemmers wrote:OK, by "CO2 guns" I meant those with the disposable canisters that Oz highlighted, which gives you the 4 main types of air gun:
- Springers
- Single Stroke Pneumatic (SSP)
- Disposable canister (invariably containing CO2)
- Pre-Charged Pneumatic (PCP)
If you want to put CO2 in a PCP instead of air that's fine! Out of interest why? I can't imagine it's any cheaper to source CO2 than standard air (unless you work in a lab with CO2 on tap!).
If you don't understand why some people prefer them to PCP then you should look back through the many previous threads on the topic. This "discussion" on TT has been going on for as long as I can remember.
Found a few, but I don't understand what the difference is or why people favour CO2/air respectively.
Surely it's basically the same mechanism? It just comes down to a refillable cylinder that fits into a valve/trigger mechanism on the gun.
I'm sure if you wanted to badly enough you could fill a PCP cylinder with CO2, and a CO2 cylinder with air, so I don't understand the difference.
Or is this the theory that certain gases don't change density as much with changes in temperature, etc and give more consistent results/better performance in a variety of conditions, leading to people experimenting with non-air gases. Some inert, some *ahem* not.
Surely it's basically the same mechanism? It just comes down to a refillable cylinder that fits into a valve/trigger mechanism on the gun.
I'm sure if you wanted to badly enough you could fill a PCP cylinder with CO2, and a CO2 cylinder with air, so I don't understand the difference.
Or is this the theory that certain gases don't change density as much with changes in temperature, etc and give more consistent results/better performance in a variety of conditions, leading to people experimenting with non-air gases. Some inert, some *ahem* not.
A significant benefit offered by refillable CO2 is a consistent pressure right up until the CO2 is nearly gone. The CO2 remains liquid until released from pressure, at which point it violently converts back into a gas. The idea of having nearly identical propellant pressure for all shots in a match is intriguing. As I shoot my LP-10, every shot I take is sent down-range by a slightly different PSI (or BAR) value. Each shot, no biggie. From shot #1 to shot #60, it's a significant difference.
Up until this year, a CO2-based Steyr LP-1 held the world record set in 1989. 593. Just this year, that record was finally broken by a compressed air Steyr LP-10. 594.
The only downside is that CO2-based arms are indeed sensitive to ambient temperature. Too cold, the CO2 doesn't vaporize quickly enough, too hot, the CO2 vaporizes too soon. Refilling also requires a little more attention since you refill by weight. I understand that ideally, one should place a CO2 cylinder in the freezer before refilling --to get keep as much CO2 in liquid form as it is pushed into the cylinder.
Oz
Up until this year, a CO2-based Steyr LP-1 held the world record set in 1989. 593. Just this year, that record was finally broken by a compressed air Steyr LP-10. 594.
The only downside is that CO2-based arms are indeed sensitive to ambient temperature. Too cold, the CO2 doesn't vaporize quickly enough, too hot, the CO2 vaporizes too soon. Refilling also requires a little more attention since you refill by weight. I understand that ideally, one should place a CO2 cylinder in the freezer before refilling --to get keep as much CO2 in liquid form as it is pushed into the cylinder.
Oz
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David Levene
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David Levene
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- Location: Ruislip, UK
Another big benefit for some of course is that they find it much easier to get CO2 than have scuba tanks refilled. We are lucky here in the UK in that most people will be within relatively easy driving range of a dive shop.Oz wrote:A significant benefit offered by refillable CO2 is a consistent pressure right up until the CO2 is nearly gone.
Are you sure about that. If the regulator is working correctly I would have thought it would be levelling any variations out.Oz wrote:As I shoot my LP-10, every shot I take is sent down-range by a slightly different PSI (or BAR) value. Each shot, no biggie. From shot #1 to shot #60, it's a significant difference.
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Steve Swartz as Guest
Hemmers:
No, CO2 and PCP are definitely *not* "interchangeable" in any sense of the word. The two systems are completely different. The entire mechanism of each type of pistol differ substantively.
The systems are different. Each has its own advantages and disadvantages as thoroughly discussed in some fairly recent threads. CO2 is the "old" systems and PCP is the "new" technology. Many matches and clubs no longer support CO2 systems at all.
Either system will shoot as many tens as you are capable of. It's a matter of tradeoffs between cost and convenience.
No, CO2 and PCP are definitely *not* "interchangeable" in any sense of the word. The two systems are completely different. The entire mechanism of each type of pistol differ substantively.
The systems are different. Each has its own advantages and disadvantages as thoroughly discussed in some fairly recent threads. CO2 is the "old" systems and PCP is the "new" technology. Many matches and clubs no longer support CO2 systems at all.
Either system will shoot as many tens as you are capable of. It's a matter of tradeoffs between cost and convenience.
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luftskytter
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"Serious" PCP guns for match competition have regulators and manometers. This means the working pressure of the mechanism is constant, and you can check how much air is left in the cylinder.
CO2 guns don't need these refinements.
With CO2 you need special gaskets/O-rings, so a PCP gun is not CO2 compatible. To fill a CO2 gun with liquid gas, you need to cool down the cylinder (appr. 5 inutes in the freezer) before filling.
Because the CO2 is stored as liquid, the shot capacity is pretty high despite lower pressure than PCP.
CO2 guns don't need these refinements.
With CO2 you need special gaskets/O-rings, so a PCP gun is not CO2 compatible. To fill a CO2 gun with liquid gas, you need to cool down the cylinder (appr. 5 inutes in the freezer) before filling.
Because the CO2 is stored as liquid, the shot capacity is pretty high despite lower pressure than PCP.
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Freepistol
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I thought that, too, David.David Levene wrote:Are you sure about that. If the regulator is working correctly I would have thought it would be levelling any variations out.Oz wrote:As I shoot my LP-10, every shot I take is sent down-range by a slightly different PSI (or BAR) value. Each shot, no biggie. From shot #1 to shot #60, it's a significant difference.
I figured, for instance, assume it takes 40 bar to propel a pellet. So from a 200 bar cylinder, there would be no velocity difference until one approached the 40 bar, at which time the latch on my Morini would prevent continued shooting.
Does it work differently?
I'm sure the regulator is fine. I simply didn't give it enough credit. The variance in pressures is going to be statistically insignificant until the tank pressure falls below the regulation point.Freepistol wrote:I thought that, too, David.David Levene wrote:Are you sure about that. If the regulator is working correctly I would have thought it would be levelling any variations out.Oz wrote:As I shoot my LP-10, every shot I take is sent down-range by a slightly different PSI (or BAR) value. Each shot, no biggie. From shot #1 to shot #60, it's a significant difference.
I figured, for instance, assume it takes 40 bar to propel a pellet. So from a 200 bar cylinder, there would be no velocity difference until one approached the 40 bar, at which time the latch on my Morini would prevent continued shooting.
Does it work differently?
I am disappointed to see that the LP10 does NOT have a pressure cut-off. You can shoot pellets until the needle is touching the bottom peg and beyond. I've done it. To hit the target I was raising the pistol higher and higher to keep the pellets on the target.
Oz
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Steve Swartz as Guest
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Shooting Bloke
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Ah, I see, liquid CO2, same as the disposable canisters. I was imagining gaseous CO2 - Such a system would be essentially the same as PCP, obviously a liquid CO2 system would not be! Not come across them before.
As David says, I know a half dozen dive shops and gun shops where I could get a refill of breathing quality air into a buddy bottle or direct to a cylinder.
But refills of CO2? No idea. I suppose one could approach an electronic engineering or chemistry mate who might be able to get it through the lab or clean room supply, but commercially? No idea.
As David says, I know a half dozen dive shops and gun shops where I could get a refill of breathing quality air into a buddy bottle or direct to a cylinder.
But refills of CO2? No idea. I suppose one could approach an electronic engineering or chemistry mate who might be able to get it through the lab or clean room supply, but commercially? No idea.
CO2 is easily obtainable from welding supply shops, fire extinguisher dealers, and beer/soda distributors. It may be purchased for home use in 5, 10, and 20 pound (contents) cylinders.
I was surprised to learn that much of the CO2 is captured from brewery fermentation tanks and would otherwise be vented to the atmosphere.
I was surprised to learn that much of the CO2 is captured from brewery fermentation tanks and would otherwise be vented to the atmosphere.