Spring Piston or Gas Ram? A Beginning Shooters Perspective – Part One
Spring piston or gas ram? That was a question which struck me multiple times as I looked for my next airgun.
As I was looking for my next air rifle, I noticed that nearly half of the break barrel offerings on a popular web site use gas ram, rather than spring piston propulsion. Curious as to the difference, I began internet searches of sources describing the advantages of break barrel air guns powered by gas rams.
Manufacturers were claiming lighter guns, with shorter lock times, less vibration and improved accuracy in the field. They also claim gas ram guns don’t freeze up in Winter. Another benefit is said to be that hunters can keep their gun loaded and cocked for extended periods without concerns for damaging the integrity of the gas piston.
Continued search disclosed that gas ram air guns have been with us for nearly 40 years. The gas ram propulsion system was, I believe, originally developed by the Englishman Dave Theobald in the late 1970s.
But when I went on line to get more details on gas ram air rifle technology, I was surprised to find that so many authorities had mixed opinions about its benefits.
So I shot off an e-mail to HAM Published Stephen Archer, seeking his opinion about spring piston or gas ram technology.
Here’s Steve’s reply…
“Ron: I don’t know all the latest thinking on this subject, but I can tell you my personal opinion. I find the “sharper” action of gas ram guns to provide no benefit in accuracy – in fact I find gas ram guns less pleasant to shoot than springers. It’s interesting that some high end manufacturers – Weihrauch, Air Arms etc. continue to make spring guns and have not moved into gas rams. Only Diana and Walther of the higher-end manufacturers (I believe) have gone to some gas ram models, but by no means all”.
Time to find out what other experts thought about the field accuracy potential of spring piston or gas ram airguns!
Manufacturers said their gas piston guns had much faster lock times, and equated that to greater accuracy in the field.
But they don’t tell us how to achieve that greater accuracy. Is it achieved using a delicate springer “Artillery Hold”? Or can precision shooting with their gas ram guns can be achieved if the shooter locks into his gun with a tight hold.
Using a delicate Artillery Hold on the bench is one thing, but employing that touchy feely technique while hunting in the field is another story.
One highly respected “Air Gun Expert” acknowledged that the lock times were significantly improved with gas piston technology. But he concluded that shorter lock times didn’t necessarily translate into improved accuracy.
All of the on-line opinions I researched basically agreed with HAM Publisher Stephen Archer. Faster lock times don’t contribute to greater accuracy in a gas ram air gun.
I knew I might be chasing a phantom, but I had to keep pursuing that question. Spring piston or gas ram?
If the simplicity of the break barrel gas piston air rifle could be combined with the superior accuracy of PCP guns while employing traditional bench rest technique under field condition that would be great. Shooters who can’t afford more expensive PCP guns, or who enjoy “keeping shooting accessories to a minimum” would be thrilled with my findings.
I linked to the HAM Review Center to see which current production gas ram guns “Archer and Company” had reviewed, and the HAM test team gave the Beeman Model 1051GP their Silver Award. High marks for a budget priced gun.
The Beeman Teton delivered impressive accuracy for guns in their price range. These Beeman-branded air rifles are produced by the oldest air gun manufacturer in China, Shanghai Airguns. The Shanghai factory claims center-to-center (CTC) accuracy of 0.2 Inches at 10 Meters.
No details are given about the number of shots to achieve that accuracy. But even if they were 5 shot groups, it was Light Years better than I could do with my Remington Express.
Quite coincidentally, an ad arrived in my inbox with a discount on the Beeman Teton Gas Ram. It was a chance for me to analyze the Beeman Gas Ram product tested by the HAM team.
Spring piston or gas ram? It looked like I was beginning to make progress…
Now I could see if a rookie shooter (that would be me) could prove or disprove the field accuracy potential claimed by the manufacturer, but downplayed by many of the experts in the field.
Before I began my testing, there were a few housekeeping duties I needed to attend to…
I knew the HAM test review team always tests their guns using the trigger pull weight set at the factory. But I also knew that if I was ever able to compare the accuracy of the Teton shot using conventional Bench Rest technique with accuracy attainable using springer Artillery Hold technique, I had to refine the factory trigger pull on the Teton.
Promo’s suggest that the Teton has an “adjustable trigger”, but the manual gives no details as to how the new owner can fine tune the trigger pull weight. We recommend that you NOT adjust your trigger. It may render your rifle UNSAFE. The factory setting is just fine.
But for this test, you need to know that I was using a trigger pull weight of 3 1/4 Lbs, compared to the 5 1/2 Lbs pull weight employed by the HAM team.
I also wanted to make sure my rifle was performing at the same level as the test rifle used by the HAM team, so I chronographed the Crosman (Benjamin), JSB and H&N pellets used in the test.
My Benjamin pellets (compared to the Premier Hollow Points used by HAM) and Field Target Trophy pellets produced velocities and muzzle energies nearly identical to those measured by HAM. The JSB Exact pellets I used in my test out-performed the identical pellet used in the HAM test.
Such similar, but not exactly identical results are what you would expect from testing two nominally-identical samples of the same product manufactured by a good manufacturer.
The gun delivers 1000 FPS velocities with the Crosman products, and over 17 Ft/Lbs of muzzle energy with all three pellets. Performance was consistent, and exceeded my expectations for an inexpensive break barrel gun rated at 1000 FPS.
I also charted the trajectory of Benjamin/Crosman 7.9 grain pellets given the muzzle velocity recorded in my chronograph test.
As you can see, the gun will deliver 11.5 Ft/Lbs of energy out to 40 yards. And it will do that with a trajectory which never departs from the line of sight by more than 1/3 rd of an inch when using the supplied scope and rings.
That should reduce the excess chipmunk population making tunnels under your garden fence, plugging your down spouts and nipping the new buds off of that favorite rose bush!
Stay tuned. Next time (Part II) we’ll publish the findings of my tests designed to establish whether the Beeman Teton Gas Ram 0.177 cal pellet rifle will shoot as accurately employing a traditional Bench Rest Technique, as it did employing a specialized “springer technique”.
If you’re relatively new to air guns, and thinking about the spring piston or gas ram question, I think you’ll like my findings!