spring piston outdated??

[oldnamvet]

Supposedly the advantages of the gas ram are:

Here are the benefits of the Nitro Piston:
Smoother cocking
Smoother shooting
No spring torque
No spring fatigue, even if you leave it cocked for hours
Functions perfectly in cold weather
Lasts longer than a metal spring


If all this is true, why are spring piston rifles still being produced and thriving in the market?

[A.K.A. Tommy Boy]

Supposedly the advantages of the gas ram are:

Here are the benefits of the Nitro Piston:
Smoother cocking
Smoother shooting
No spring torque
No spring fatigue, even if you leave it cocked for hours
Functions perfectly in cold weather
Lasts longer than a metal spring


If all this is true, why are spring piston rifles still being produced and thriving in the market?

Tom

I have both spring piston and gas ram break-barrels plus a few pumpers.

Here is what I think... OK ?

Best  Wishes - Tom

Here are the Claimed benefits of the Nitro Piston:

Smoother cocking > Not necessarily, I have a re-built & tuned Stoger X-3 by SteveP-52 that is the smoothest cocker & shooter that I have.

Smoother shooting > Not Necessarily  See   ^

No spring torque > True

No spring fatigue, even if you leave it cocked for hours > True

Functions perfectly in cold weather > Mine work ok in cold weather but there will be a decrease in ram pressure.   I have shot mine at -20F   
A spring will work just as good or better in "really cold weather". (provided there is NO spring tar or heavy Lub in the piston area.)   

Lasts longer than a metal spring  > Maybe.... but if you get a bad ram..maybe not. 
I have a Vantage with the original ram in it.  About 9 yrs old & still shooting strong.

[nced]

Supposedly the advantages of the gas ram are:

Here are the benefits of the Nitro Piston:
Smoother cocking
Smoother shooting
No spring torque
No spring fatigue, even if you leave it cocked for hours
Functions perfectly in cold weather
Lasts longer than a metal spring


If all this is true, why are spring piston rifles still being produced and thriving in the market?

A different point of view!
"Smoother cocking"
Not necessarily true because a coil spring with properly fitted snug spring guides are indeed smooth. A lot of "cocking roughness" has nothing to do with the coil spring but the sliding piston and cocking lever components sliding under pressure. The only difference between "rammers" and "springers" is the spring (coil or gas), the other components such as the piston, piston latching mechanism and piston seal are similar.

"Smoother shooting"
Perhaps true since factory springer setups normally use loose fitting spring guides that allow the spring to oscillate/twang/vibrate with the shot. However a properly fitted spring guide and top hat will kill twang and vibration. Considering that the "rammer" requires more cocking effort than the "springer" for equal velocity, plus the "rammer" shot cycle is sharper than the "springer" I prefer a properly fitted spring kit. Also, due to the "rammers" sharp shot cycle they're notorious for "scope killing". Also, the sharper "rammer" shot cycle means that a rammer is also more "hold sensitive" than a "springer".

"No spring torque"
This is indeed true and this term used by tuners to sell "springer" tunes. I've personally never noticed that any minute twisting during the shot cycle due to "spring torque" to be an issue with my HW springers. A couple 50 yard groups shot with my recoiling springers while sitting on a bucket resting the gun on cross sticks.......


"No spring fatigue, even if you leave it cocked for hours"
Well.....a "gas ram" contains gas under pressure ALL the time, even when not cocked (The Theoben ram is charged to about 800psi before cocking) and sealed with "orings" (or other rubber seal) and they are indeed known to leak down at times. The high end Theoben rams they can be disassembled and resealed when needed, but you still need a high pressure pump to restore the internal pressure...........

The cheap "Crosman type" rams are disposable and can't be recharged........

As far as the coil spring is concerned, when living in West Virginia I often left my .177 Beeman R9 cocked for a couple hours during squirrel hunts and the Maccari aftermarket spring (now caller ARH Air Rifle Headquarters) and I would get about 2 years of service shooting roughly 10,000 shots per year, then $20 and a half hour later the gun would be "re-powered" and good for several more years.

"Functions perfectly in cold weather"
Really? I would THINK that cold weather would reduce the internal ram precharge pressure and hot weather would increase the internal ram precharge pressure. If "functions perfectly" means that the pellet comes out of the barrel then I agree. LOL....even atmospheric conditions such as humidity, barometric pressure and temperature will affect the poi after the pellet leaves the barrel. If "functions perfectly" means the "rammer" has a more stable poi under all atmospheric conditions than a coil spring......I'm skeptical. LOL...the piston seal itself is affected by temperature causing a variable poi and the "rammer" has a "rubber" piston seal just like the "springer".

"Lasts longer than a metal spring"
LOL....that all depends of both the ram used in a "rammer" and the coil spring used in the "springer". When I used to keep track of the shot count when I had a .177 Beeman R10 I bought a Maccari "soft spring kit" (before I started home rolling my own spring kits based on Maccari springs) and after 20,000 shots the Maccari spring still shot .177 cal 7.9 grain domes at 905ish fps which was only 5fps less than the 910ish fps when new. LOL....atmospheric variations and the successive shots over the chrony can vary more than that.

"If all this is true, why are spring piston rifles still being produced and thriving in the market?"
Hummm.....maybe all the above are simply sales pitches to sell guns to new shooters. I've shot piston class field target matches for a few decades and I've noticed that the shooters who show up with a "low cost rammer" don't continue with the "rammer" and change the gun to a "springer", or more likely one the newer lower cost PCPs.

LOL.....for a few seasons now, when I show up at a field target match to shoot "hunter class" with my .177 HW95 springer I'm usually the only "piston shooter" and "win" 1st.2nd, & 3rd place all by myself!

[BigBird]

If all this is true, why are spring piston rifles still being produced and thriving in the market?

They are usually cheaper however it seems like a lot of high end break barrels have them too but these high end guns also don't have the issues in Tommy Boys claimed benefit list (e.g. they are smooth cocking, smoother shooting, less hold sensitive, etc.).

[SpiralGroove]

If all this is true, why are spring piston rifles still being produced and thriving in the market?

Gas rams can leak, which can be a pain; they need to be re-sealed and pumped up again.  Thus, the need for a PCP air pump.  However, this can be a benefit too as you can adjust gun velocity if desired... instead of replacing the spring or clipping coils.

Gas rams are smoother, but the ones I've tried required a steady force throughout the cocking cycle.  True Springers, on the other hand, start hard and get easier near towards the end of the cocking motion. I prefer the latter...

[SteveP-52]

If all this is true, why are spring piston rifles still being produced and thriving in the market?

Random dumb thought but springs are easier to make, likely less expense to make than gas rams and more to potentially go wrong with a gas ram than a spring making for more customer service hassles, especially if you get a bad batch and now have say 2000 rifles with bad ones in them. Not all gas rams can be tinkered with either. Hatsan you can if you're careful. Crosman I believe are sealed units and not adjustable. The offerings from Diana and the new Sig ASP I can't speak for having never seen either and don't recall anyone saying they've been inside one to have a look at the rams. While you can do any number of things to a spring powered rifle, not all those tuning tricks can be done to a gas rammed gun, especially if you have a sealed ram.

Also read enough on this forum to know even the high end rifles suffer from any number of possible issues. Just because you pay a premium, doesn't mean you'll get a trouble free rifle and it's been well documented in any number of Gates here.

[Pandur_HR]

About temperature sensitivity.

I don't have a springer to compare, but I have a nitro piston, and I spent some time to chrono it in different temperature conditions to setup ballistic calculator correct. Here are results:



From 0-25C Speed is calculated correct now (clean barrel), later when it become warmer, I will check above 25C. Below 0C, I avoid shooting.

POI @100m shift 10 cm, 5-25 C. 1 dot, at similar barometric pressure and humidity. Verified by actual shooting.

Here are other settings if anyone need.

[c_m_shooter]

I have both and don't see any of the claimed benifits of the gas ram in use.  It comes down to the quality of the gun and tune, not the power plant.  My gas ram rifle is more hold sensitive than either of my spring piston rifles, but that may be just due to its power level. They tested the temp sensitivity due to cold on American Airgunner by putting 2 rifles in a deep freezer then shooting them.  The gas ram was the worse of the 2 they tested.

[anti-squirrel]

I think in the largest calibers (.25 and .30) you end up with a more forgiving airgun if it uses gas-ram.  My Hatsan 95QE is a .25 as as it has "aged" it seems to be completely indifferent to how I hold it.  The thing I aim at (99% of the time it is a squirrel) is hit.

I'll qualify that I've only shot one .25 steel-spring springer- fresh out of the box so not broken in yet.  Aside from the much more prominent twang, it shot accurately but was far more hold sensitive.


Out of the box and without any tuning/cleaning/adjustment, the gas piston guns shoot better, especially at magnum power levels.  Once tuned, though steel spring guns do excellent.  Operative words: Once tuned.  Not everybody wants to tune.

[mikeyb]

Sometimes SIMPLE is good enough!

Coil spring air rifles are unlikely to be completely displaced any time soon.

I'm uncertain which marketing department came up with the term "gas ram", but I try NOT to use it since IMO it is not really correct.

They are BOTH springs. One is a dirt simple tempered metal wire spiral, the other is a high pressure (1000-3000 psi) compressed gas (air or nitrogen) cylinder with a sliding piston, internal lubrication (oil), a sliding piston SEAL, and sometimes a port w/checkvalve for degassing and refilling.

I'll use Crosman as an example. Until recently their coil spring was $6 and the equivalent fpe nitrogen gas spring was $27 when you ordered parts over the phone. Seems quite reasonable based on the complexity of the parts.

Most don't seem to understand how the two differ so I'll try to explain here.

Coil springs are rated by force/inch of deflection, like ~40lbs/in for the Crosman spring.
Gas springs are a bit different in that the force/displacement curve is MUCH flatter.
Both springs store the SAME amount of potential energy for each shot!

see attached graph...

Preload is ~2” for the coil spring.
Preload is ~0.2” for the gas spring
Displacement (piston travel) for both springs is ~4”
Same ~53 ft-lbs energy is stored in BOTH springs.
Stored ENERGY is the AREA under the curve for each line between 2" and 6" (4" displacement).
This is consistent for a typically 16 fpe (~30% efficiency) springer.

Note:
Coil spring rate at k~40 lbs/inch with 2" preload will need 80-240 lbs from start to piston lock.
This is WHY cocking springers starts relatively easy and gets HARDER.

Estimated Nitrogen pressure is ~70bar for the Crosman geometry gas spring and this translates to 140-180 lbs from start to piston lock.
This is WHY cocking the Nitro Piston rifles starts HARDER than equivalent springers, effort stays fairly constant, and effort is actually LIGHTER than equivalent springers just before piston latch.

I have many air rifles with coil springs and gas/air springs. I enjoy shooting all of them. When EVERYTHING is working normally, there is NO clear winner here based solely on the source of the stored energy.

[lefteyeshot]

I have a few gas rams but I really don't care for them. I prefer springers. It's as simple as that. I am enjoying co2's a little now but it's just so easy. After shooting my new AR2078 T.H. and AR2078B I thought about a Chieftain till I remembered pumps, tanks, probes and all that. No thanks.

[uglymike]

I recently tried my first gas ram rifle, a Diana AM03 Stealth .22. It'll be for sale @ the GTA gathering, cheap. Give me a well tuned springer any day.

[xtred1]

These companies are in the game to make money.  Many times perception of value sells products.  When you look at what companies like Crossman are trying to do, that is grabb a bunch of the PB market in the US. If it says Hemi on the side or shoots a claimed 1200 fps that sells. When the real truth is almost all cars and trucks on the road have some form of a hemi head, and speed by itself does not make a good air rifle. The perception is what sells. I think the gas ram the way it has been marketed  and sold in the US is really more about perception the reality.

[fwbsport]

I've got one HE gas ram for the only reason it's good for: killing things.  Since I don't do that often the gun has stayed in tune and up to service since I took it out of the box 20 years ago.

Despite this plus added for the HE gas rams made today at lower cost than the antiquated Eliminator (and even the RX2 by Ruger) I can't say how useful they'd be to frequent shooting day in and day out.

However I love my springers with coils better for ease of shooting!

[mata777]

I’ll take a tuned spring piston gun over a gas piston version any day. 

[Matchstickshooter]

I’ll take a tuned spring piston gun over a gas piston version any day.

Never had a gas piston. Don't need one.

[UlteriorModem]

I’ll take a tuned spring piston gun over a gas piston version any day.

Why in the long run it is just two different ways to accomplish the same task.

[UlteriorModem]

Oops double post

[dan_house]

If you get a gas ram from the big box store (read that: sub $200) its likely over-powered and violent to shoot

Ive got one of the original Benjamin NPSS soft stock rifles in .22 . Very nice gun to shoot--after you get the hang of what its doing. The sub$100 f4 fury is harsh, overpowered.

GasRams are great, BUT they need to be matched to the gun's audience and expected usage.

Speed sells, but these cheap rammed guns are NOT an example of what the benefits of the power plant can be.

[nced]

I’ll take a tuned spring piston gun over a gas piston version any day.

Why in the long run it is just two different ways to accomplish the same task.

Yes......both a gas and coil spring accomplish the same task, however the shot cycle is different. The gas ram shot cycle is harsher than a coil spring shot cycle with a similar weight gun shooting at similar velocities and it takes more cocking effort vs the coil spring. Also, the gas ram shot cycle is a known "scope buster".

Decades ago I shot a stock .25 cal Beeman Kodiac (rebadged Webley Patriot springer) the put out a measured 30fpe with Diana Domes and I had no problem cocking the gun for a half dozen shots. Then I had the opportunity to shoot a .20 cal Beeman Crow Magnum (rebadged Theoben Eliminator rated at 25fpe and 28fpe in .25 cal) and it was a GUT BUSTER to cock even though it was putting out less fpe. After shooting 3 shots my "cocking arm" was shot and I decided that if I were given an Eliminator I'd simply sell it.