N/A Springer power mods tips??

[Sawney Bean]

10,000 psi of compressed air won't drive a projectile any faster than 8,000 psi. Compressed air simply does not have the physical capacity to expand that rapidly behind a projectile moving faster than about 1800 fps. (I think that's the number, it's close).

Yes it would be expensive to shoot a helium gun. Yes the seals and rifle would need to be reingineered. But a rifle designed to use a light gas will shoot MUCH faster than any rifle that uses compressed air. And guys would buy them. And they will have problems inherent to the venture.

The heat from a powderburner goes out the barrel as gas. Very little transfers. A powderburner barrel gets hot from friction. Not the explosion. An airgun barrel will get almost as hot as a powderburner with the same friction. The heat from the gunpowder explosion is rapidly expanding gas that exits the barrel. It's only in there a microsecond and does not transfer with convection to the gun metal. Just as the superheated air in a springer does not transfer into the parts. It's not enough duration to heat things up. Just burn the surface of the seal from the flash.

The friction of the projectile in the barrel is 90% of the heat that is leftover after the shot. The heat from the explosion exits the barrel as hot gas and very little is transferred.

Actually, it usually will drive it faster, particularly in a very short barrel. They may have an almost identical maximum velocity, (pressure has a small effect on the speed of sound), but we usually aren't firing airguns at their maximum velocity anyway, so having 2000 extra psi will absolutely allow for faster acceleration of the projectile, (same velocity from a shorter barrel), more kinetic energy with the same length barrel, more shots per charge, etc... Just imagine that you had a PCP that was limited to 1500 psi. Sure, you could make it work, but having 4500 psi gives you a lot more design options.

The heat generated in a PB absolutely can be a problem. In the G11 caseless cartridge rifle one of the biggest problems they had was heat buildup. In a conventional rifle much of the heat gets expelled by the empty cartridge cases. In the G11 they had to develop ceramics and special lubes to keep it functioning at unusually high heat. The same issue affects direct impingement rifles to a much lesser degree. Heat is also one of the things that PB suppressors must be designed for. Bottom line is that heat is absolutely a problem that firearms have to deal with and the closest thing airguns experience is a cooling effect from gas expansion.

You should also check out the price of helium. Where I live a 81 cf tank refill is $185. How many airgunners are going to want to pay that kind of money per tank? https://www.mmballoons.com/buy-helium-tanks/

 

[wgd]

Mike Ellingsworth rammed and tuned a 135 in .25 for me many years ago.It was above 30 fpe and a beast.i could only occasionally shoot under inch at 25 yards but it worked as a good Eurasian Dove killer.The gun died when the barrel slipped out of my hands while cocking it in freezing weather. (yes ,both hands needed to cock the beast)
The barrel bent so bad It could shoot around corners....

2 hands to cock huh? That’s crazy. Last thing I need at 73 is surgery for a hernia . Guaranteed that’s what would happen. I pulled a stomach muscle a couple months ago shooting my new 95N. Not from cocking difficulty, from too many rounds the day I first bought it. I found when I first started shooting springers I needed to get in cocking shape!

 

[longdog]

10,000 psi of compressed air won't drive a projectile any faster than 8,000 psi. or 6,000 psi. Compressed air simply does not have the physical capacity to expand that rapidly behind a projectile moving faster than about 1800 fps. (I think that's the number, it's close).

Yes it would be expensive to shoot a helium gun. Yes the seals and rifle would need to be reingineered. But a rifle designed to use a compressed light gas will shoot MUCH faster than any rifle that uses compressed air. Guys would buy them. And yes they will have problems inherent to the engineering.

The heat from a powderburner goes out the barrel as gas. Very little transfers. A powderburner barrel gets hot from friction. The hot gas is only in there a microsecond and does not transfer with convection to the gun metal (much). Just as the superheated air in a springer does not transfer into the parts. It's not enough duration to heat things up. It just burns the surface of the seal from the flash and then it's gone.

The friction of the projectile in the barrel generates most of the heat that is leftover after the shot. An airgun barrel shooting a bullet at rifle speeds with the same rifling engagement will get (almost) as hot as a powderburner.

...at least that is what some guy told me and I believed him. I could be totally wrong.

You are one smart dude…….you explain what’s going on in every thread that you comment in.

 

[Bedrock Bob]

You are one smart dude…….you explain what’s going on in every thread that you comment in.

Yes and I can see that bothers you a little.

...I kinda like that!

 

[Bedrock Bob]

Actually, it usually will drive it faster, particularly in a very short barrel. They may have an almost identical maximum velocity, (pressure has a small effect on the speed of sound), but we usually aren't firing airguns at their maximum velocity anyway, so having 2000 extra psi will absolutely allow for faster acceleration of the projectile, (same velocity from a shorter barrel), more kinetic energy with the same length barrel, more shots per charge, etc... Just imagine that you had a PCP that was limited to 1500 psi. Sure, you could make it work, but having 4500 psi gives you a lot more design options.

The heat generated in a PB absolutely can be a problem. In the G11 caseless cartridge rifle one of the biggest problems they had was heat buildup. In a conventional rifle much of the heat gets expelled by the empty cartridge cases. In the G11 they had to develop ceramics and special lubes to keep it functioning at unusually high heat. The same issue affects direct impingement rifles to a much lesser degree. Heat is also one of the things that PB suppressors must be designed for. Bottom line is that heat is absolutely a problem that firearms have to deal with and the closest thing airguns experience is a cooling effect from gas expansion.

You should also check out the price of helium. Where I live a 81 cf tank refill is $185. How many airgunners are going to want to pay that kind of money per tank? https://www.mmballoons.com/buy-helium-tanks/

Well then a light gas pellet gun is a mighty silly idea isn't it?

I feel dirty all over for suggesting such a thing.

The speed of sound is 3x faster in helium than air. So you do the math on how fast you can push a projectile with it.

The gun I saw shot a pellet at 20,000 fps.
but it used hydrogen and was 40 feet long. I think a smaller one using helium would be cool even if you could only get a fraction of that velocity.

I understand that you may not agree and I respect that completely. I was just thinking about the topic of how to make a spring gun go faster and thought I'd present an idea based on the fastest "springer" I'd ever seen. If you don't find the idea interesting then that's fine too.

 

[Sawney Bean]

Well then a light gas pellet gun is a mighty silly idea then isn't it?

I feel dirty all over for suggesting such a thing.

It's an interesting idea for a gun designed to break records or test performance and I can see where long range bench rest shooters might want to try it. For practical purposes however, I can't see it.

 

[Bedrock Bob]

It's an interesting idea for a gun designed to break records or test performance and I can see where long range bench rest shooters might want to try it. For practical purposes however, I can't see it.

Most guns aren't practical.

Most air guns posted on this forum are highly specialized. They are only practical for specific purposes. Others are impractical by virtue of cost. Many have impractical stocks. Impractical scopes. Impractical calibers.

The topic started out challenging practicality.

I just pointed out that for maximum speed we are using an impractical gas in our impractical rifles.

If practicality is a requirement we're all screwed. We are shooting spring piston pellet guns for heavens sake!

 

[longdog]

Yes and I can see that bothers you a little.

...I kinda like that!

Quite the contrary…..your comments are quite amuzing.

 

[.20calguy]

I didn't read every post in your thread, but I didnt see anyone mention the springer barrels being designed for pellets. Slug barrels have different chokes and twist rates.

 

[Bedrock Bob]

How about a rifle with a monster gas piston too stff for a shooter to cock. Let's say 300 lbs cocking effort with the ability to adjust the gas pressure. The ram is filled with a light gas and to adjust the pressure it would need a small high pressure helium tank to add gas/pressure.

Instead of a break barrel use an underlever or side lever to compress this muscular piston. But instead of cocking with a simple lever in one stroke use a cam and a ratchet (like a handyman jack) to compress the piston with multiple strokes. Like a pumper.

You could compress a mighty piston and still cocking effort would be manageable. You would just have to use multiple strokes to get it there.

You could utilize much of the extra speed of a light gas using a sealed gas piston. It would only need to be topped off with pressure occasionally, and the cam and ratchet would make it possible to operate.

You could shape the transfer port like the light gas gun to maximize compression force and multiply the pressure. And install a valve much like the trigger valve on a PCP so that pressure would be high before the valve opened and started the pellet. You could easily equal the volume and compression of a PCP if your swept volume and impulse pressure of the ram was adequate.

You could match that powerplant with a barrel that shot .22 cal slugs. Maybe a slug in a sabot to minimize friction. Maybe a slug with a plastic jacket that didn't separate from the projectile (think powerbelt bullets).

You could put pressure in that gas ram until the recoil knocked the dentures out of your mouth. And put whatever length/weight slug in your sabots. The slugs could be just lead wire cut to length without swaging or formed with a hollow point to provide expansion. The sabots could be formed to provide the perfect size and shape for performance.

You would have a fully adjustable gas ram springer with much more potential velocity and the ability to use a wide variety of projectiles.

A cam and ratchet lever and a bigger cylinder would add weight and bulk. You might lay that cylinder under the barrel rather than behind it to limit length. Maybe put the cocking handle and ratchet in your pocket to reduce weight.

You wouldn't spend as much on gas as a PCP. It would only need topping off occasionally. The speed would be comparable to a PCP with a large volume cylinder. And the start pressures would be adjustable like a PCP too. You could "tune" the rifle for both thrust pressure and dwell time with the transfer port valve and the pressure in the ram.

The only issue would be cocking the ratchet handle 4-5 times to compress your cylinder. And keeping your retinas attached after you pulled the trigger.

 

[Sawney Bean]

How about a rifle with a monster gas piston too stff for a shooter to cock. Let's say 300 lbs cocking effort with the ability to adjust the gas pressure. The ram is filled with a light gas and to adjust the pressure it would need a small high pressure helium tank to add gas/pressure.

Instead of a break barrel use an underlever or side lever to compress this muscular piston. But instead of cocking with a simple lever in one stroke use a cam and a ratchet (like a handyman jack) to compress the piston with multiple strokes. Like a pumper.

You could compress a mighty piston and still cocking effort would be manageable. You would just have to use multiple strokes to get it there.

You could utilize much of the extra speed of a light gas using a sealed gas piston. It would only need to be topped off with pressure occasionally, and the cam and ratchet would make it possible to operate.

You could shape the transfer port like the light gas gun to maximize compression force and multiply the pressure. And install a valve much like the trigger valve on a PCP so that pressure would be high before the valve opened and started the pellet. You could easily equal the volume and compression of a PCP if your swept volume and impulse pressure of the ram was adequate.

You could match that powerplant with a barrel that shot .22 cal slugs. Maybe a slug in a sabot to minimize friction. Maybe a slug with a plastic jacket that didn't separate from the projectile (think powerbelt bullets).

You could put pressure in that gas ram until the recoil knocked the dentures out of your mouth. And put whatever length/weight slug in your sabots. The slugs could be just lead wire cut to length without swaging or formed with a hollow point to provide expansion. The sabots could be formed to provide the perfect size and shape for performance.

You would have a fully adjustable gas ram springer with much more potential velocity and the ability to use a wide variety of projectiles.

A cam and ratchet lever and a bigger cylinder would add weight and bulk. You might lay that cylinder under the barrel rather than behind it to limit length. Maybe put the cocking handle and ratchet in your pocket to reduce weight.

You wouldn't spend as much on gas as a PCP. It would only need topping off occasionally. The speed would be comparable to a PCP with a large volume cylinder. And the start pressures would be adjustable like a PCP too. You could "tune" the rifle for both thrust pressure and dwell time with the transfer port valve.

The only issue would be cocking the ratchet handle 4-5 times to compress your cylinder. And keeping your retinas attached after you pulled the trigger.

To some degree, this describes the Theoben Dual Magnum. It was a gas ram rifle that had two power levels, took two strokes to cock fully and developed 36 fpe. They were produced in very low numbers and are super collectible today. Somebody was selling one here recently for $4500 and it might still be on the classifieds.

 

[Arzrover]

To some degree, this describes the Theoben Dual Magnum. It was a gas ram rifle that had two power levels, took two strokes to cock fully and developed 36 fpe. They were produced in very low numbers and are super collectible today. Somebody was selling one here recently for $4500 and it might still be on the classifieds.

OR a Whiscombe...
The JW80 needed 3 cycles of the cocking lever and is one of the most powerful springers out there... but it's minus all the extra gas stuff and still portable enough to be useful for airgun stuff...
Bob

 

[Bedrock Bob]

To some degree, this describes the Theoben Dual Magnum. It was a gas ram rifle that had two power levels, took two strokes to cock fully and developed 36 fpe. They were produced in very low numbers and are super collectible today. Somebody was selling one here recently for $4500 and it might still be on the classifieds.

Bingo!

The light gas contained in a ram is the best of both worlds. It makes use of the faster gas without using it directly for the pellet pressure. It's not as fast as a light gas gun but much more practical.

Sooner or later someone will revisit the idea and make another one. It's about the only practical solution to make a springer more powerful and still be able to cock it.

I like the feel of the gas ram better than a spring. And they perform better at altitude and in cold weather. I bought a gas ram cometa just to see what all the hype was about and I'm impressed. Its light. It cocks smooth and easy and gets 740 fps (.22, 14.6 pellets, 4000 fas). The shot cycle is smooth and the recoil is not bad at all. The big Gamo the OP is shooting sounds like a step up from there. I think the limiting factor from a practicality standpoint would be recoil and not speed with a gas ram. Once it kicks too much to shoot accurately a pressurized gas to drive the pellet starts to make more sense.

 

[Sawney Bean]

Bingo!

The light gas contained in a ram is the best of both worlds. It makes use of the faster gas without using it directly for the pellet pressure. It's not as fast as a light gas gun but much more practical.

Sooner or later someone will revisit the idea and make another one. It's about the only practical solution to make a springer more powerful and still be able to cock it.

Yeah, I like gas rams a lot. In my experience they just seem to inherently have less twang and hold sensitivity than a steel spring, plus there's the option of adding or subtracting gas with the gun still mostly assembled.

I'd really like to someone build a monster gas ram gun with say a 38mm tube and to hell with practicality. Just make it the springer equivalent of a .500 S&W, a stupidly big and powerful spring piston airgun designed for bragging rights and entertainment.

 

[BABz58]

You are one smart dude…….you explain what’s going on in every thread that you comment in.

I concur

 

[Bedrock Bob]

Yeah, I like gas rams a lot. In my experience they just seem to inherently have less twang and hold sensitivity than a steel spring, plus there's the option of adding or subtracting gas with the gun still mostly assembled.

I'd really like to someone build a monster gas ram gun with say a 38mm tube and to hell with practicality. Just make it the springer equivalent of a .500 S&W, a stupidly big and powerful spring piston airgun designed for bragging rights and entertainment.

Agreed. Even if you had to wear a mouthpiece and heavy gloves to shoot it. A gas ram artillery piece cocked with a Harbor Freight hydraulic jack. Just light enough to lift onto a rest with a back brace.

I saw a guy make a ram cylinder from a motorcycle front fork on YouTube. I bet that sucker would toss a slug through a brick wall.