GTA
All Springer/NP/PCP Air Gun Discussion General => European/Asian Air Gun Gates => Turkish AirGun Gate => Topic started by: Dan Jefferies on October 23, 2017, 07:39:29 PM
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Like my mama said I'm dumb as a box-o-rocks so bear with me. If this is the wrong section see my previous statement.
The 135 in all configurations (177-30 cal) has a 10.9 inch barrel MUCH shorter than the 125. It also has a greater swept volume. I believe the barrel length was chosen to accommodate the 30 caliber version and with its greater swept volume the smaller calibers kept their fps ratings. So while the .30 caliber uses all the air available the smaller calibers are wasting a LOT of air.
My proposal is to use a .25 caliber 125 barrel on a .25 caliber 135. It should fit no problem. Sounds like a major power boost to me.
Good, Bad, Ugly? All comments welcome ...)
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I'd say put an H&N 19.91 .25 over a chrony and see what the 135 does.
I know I got near 750 FPS in the 125 Sniper.
Will Chrony the 135 with that same pellet in a few days when I get home.
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My 135 springer shoots H&N FTT 19.91g @ 827 fps for 30.1 fpe.
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I'd say put an H&N 19.91 .25 over a chrony and see what the 135 does.
I know I got near 750 FPS in the 125 Sniper.
Will Chrony the 135 with that same pellet in a few days when I get home.
Please do...19.91? So you have the .22 caliber 135? *edit* My reading comprehension skills seem to be lacking....
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My 135 springer shoots H&N FTT 19.91g @ 827 fps for 30.1 fpe.
At your speed you're getting 30.24 fpe...If a simple barrel change ups it to 1000 fps (just 173 fps) that would come out to 44 fpe ...wow... that's why I'm so interested ... 2 extra inches just might add, just, add the 173 fps needed...*edit* at 950 fps, just 123 fps more your power would be a solid 40 fpe... still wow....
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To change a barrel and increase speed you'd be changing the caliber. 1000 fps barrel is .22 cal shooting 14 grain from a 125, 135 power plant. You can't change the energy of a gun by changing out the barrel unless the barrel is shorter than potential energy to develop shot by time it exits barrel. The power these break barrels put out only need a 10 inch barrel or less. They are longer simply to act as a lever to cock the gun.
I know what your saying in that the 135 and 155's have larger diameter piston chambers. It stands to reason they'd have some percentage more power than the 125. It was not enough to promote. Variances from gun to gun are as much or more than the <10% theoretical gain from added chamber volume. I believe Hatsan never promoted the 135 and 155's as more power as any testing it would be hard to prove. A good shooting stock 125 can still outshoot a so so shooting 135 so what's to promote?
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My non-QE 135 springer has the 17.7" barrel already. The QE version 135 has the 10.6" barrel. I have a 125 sniper springer with the same length barrel as well.
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To change a barrel and increase speed you'd be changing the caliber. 1000 fps barrel is .22 cal shooting 14 grain from a 125, 135 power plant. You can't change the energy of a gun by changing out the barrel unless the barrel is shorter than potential energy to develop shot by time it exits barrel. The power these break barrels put out only need a 10 inch barrel or less. They are longer simply to act as a lever to cock the gun.
Respectfully disagree... The silencer housing welded to the front of the barrel is the lever. The actual barrel is internal and much shorter than what you see... I think
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[/quote]My non-QE 135 springer has the 17.7" barrel already. The QE version 135 has the 10.6" barrel. I have a 125 sniper springer with the same length barrel as well.
Stipulated that we are speaking of the 10.6 inch QE version.... thanks for the heads up...
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I believe I wasn't clear about power being wasted... I'm not trying to wring blood from a stone I just believe that a lot of power is being wasted by the shorter barrel of the 135 QE in smaller calibers other than the .30 cal...
Here is a short GTA thread to bring us up to speed..
https://www.gatewaytoairguns.org/GTA/index.php?topic=26322.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=26322.0)
here's a quote from the thread
"A Hatsan 135 in .177 caliber would need a barrel that was over 30 inches long before it used up all the available energy in the air. You can make the barrel shorter and it will work fine, but you are wasting some of that large chamber volume. For comparison, a .25 has 100psi remaining with a 15 inch barrel."
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I understand what you saying. Greater swept powerplant volume should have greater barrel volume to take advantage of what is available. So if you go down in diameter, you go out in length, provided everything maintains enough of a seal to make it work.
Could they also have reduced barrel length to alleviate some need for follow through?
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I understand what you saying. Greater swept powerplant volume should have greater barrel volume to take advantage of what is available. So if you go down in diameter, you go out in length, provided everything maintains enough of a seal to make it work.
Could they also have reduced barrel length to alleviate some need for follow through?
Don't know but the 125 with it's lower volume of air matching the 135 fps rating by utilizing a longer barrel screams to me wasted power... I messaged Scotchmo for help. To do this I'd need to buy a new block and barrel but don't want to pull the trigger without being reasonably certain of some gain. By the numbers fps would have to rise a 13 percent for 40 fpe. A 6.5 percent raise (swept volume difference is 8 percent ?) would produce about 35 fpe still a huge increase...
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You'd have to see what the crony #'s people with QE versions are getting compared to non QE versions. That's a 7 inch difference of barrel. Surely if it was significant there'd be a lot of talk and complaining on these threads about loss in 135 power since the QE change over.
I agree there must be left over potential energy but believe it's insignificant amount. The power curve is a parabola, not linear expression, and the top of that curve is nearly flat for a wide range of barrel length. Think about it, .177 in 125 or 135 is proven to be less energy. From the learned guesstamate above the length of barrel would need to be 30" to tap out all the potential. Yet the energy drop of .177 from .22 or .25 cal is only a few foot-pounds in the 17" barrels, literally about 2 FPE. If we express volumes of barrels then a a 30" .177, 20" .22, 15" .25 and 10 inch .30 are the same. If there is significant loss of energy with the QE's then it would be most seen in .177 and .22 calibers. Are people reporting 25 FPE in those calibers? That would be 3 FPE loss with 7" less barrel in .177.
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You'd have to see what the crony #'s people with QE versions are getting compared to non QE versions. That's a 7 inch difference of barrel. Surely if it was significant there'd be a lot of talk and complaining on these threads about loss in 135 power since the QE change over.
I agree there must be left over potential energy but believe it's insignificant amount. The power curve is a parabola, not linear expression, and the top of that curve is nearly flat for a wide range of barrel length. Think about it, .177 in 125 or 135 is proven to be less energy. From the learned guesstamate above the length of barrel would need to be 30" to tap out all the potential. Yet the energy drop of .177 from .22 or .25 cal is only a few foot-pounds in the 17" barrels, literally about 2 FPE. If we express volumes of barrels then a a 30" .177, 20" .22, 15" .25 and 10 inch .30 are the same. If there is significant loss of energy with the QE's then it would be most seen in .177 and .22 calibers. Are people reporting 25 FPE in those calibers? That would be 3 FPE loss with 7" less barrel in .177.
agreed , id be surprised if a barrel swap adds up to more than 1 to 2 fpe
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You'd have to see what the crony #'s people with QE versions are getting compared to non QE versions. That's a 7 inch difference of barrel. Surely if it was significant there'd be a lot of talk and complaining on these threads about loss in 135 power since the QE change over.
I agree there must be left over potential energy but believe it's insignificant amount. The power curve is a parabola, not linear expression, and the top of that curve is nearly flat for a wide range of barrel length. Think about it, .177 in 125 or 135 is proven to be less energy. From the learned guesstamate above the length of barrel would need to be 30" to tap out all the potential. Yet the energy drop of .177 from .22 or .25 cal is only a few foot-pounds in the 17" barrels, literally about 2 FPE. If we express volumes of barrels then a a 30" .177, 20" .22, 15" .25 and 10 inch .30 are the same. If there is significant loss of energy with the QE's then it would be most seen in .177 and .22 calibers. Are people reporting 25 FPE in those calibers? That would be 3 FPE loss with 7" less barrel in .177.
hmm... so there seems to be a quick way to see real world results. A gas piston swap into a springer with the longer barrel. Surely this has been done?
Also I was thinking more along the lines of a 12-14 inch barrel.
The springer version with the substantially longer barrel delivers approximately 50 fps more power correct?
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It appears to me that "stronger" spring vs vortex may be a myth explained by barrel length. . It also appears that 135 is optimized for .30 cal while the 125 is optimized for .22 cal.
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FYI... looks like the OP was on to something. Apparently, even the 30 cal version of this rifle benefits from a longer barrel. For anyone who stumbles across this post, the link below has a brief description of Richard Shear's 20in barreled 135
https://www.pyramydair.com/blog/2018/09/2018-pyramyd-air-cup-part-2/ (https://www.pyramydair.com/blog/2018/09/2018-pyramyd-air-cup-part-2/)
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There is no free lunch here.
Energy in = Energy out (almost).
Hatsan's maximum fpe ratings for the Mod135 and Mod125
.177 = 28 fpe
.22 = 33 fpe
.25 = 34 fpe
.30 = 34 fpe (N/A for Mod125)
Note that the Mod135 theoretically has about 7% more swept volume in its compression chamber, yet Hatsan rates both power plants the same. Most likely because there is MORE than 7% variability from rifle to rifle and test results from Mod125 and Mod135 rifles frequently overlap. If that 7% is not rock solid reproducible, marketing that small difference would be a BAD idea.
The 135 powerplant from Hatsan is designed to generate 34 fpe in the 30 cal using a 10.6" barrel. You MAY be able to eek out another fpe or two with a longer barrel in THAT caliber, but then everyone would COMPLAIN it was TOO LONG with the QE shroud added. The Hatsan engineers are not dummies. They determined that a longer barrel in 30 cal provided minimal or NO gain so 10.6" works "good enough" and keeps this already LARGE rifle from becoming a 5' laughing stock (pun intended).
As for the amazing 20" barrel full custom 57 fpe Mod135 prototype in the link, can I quote from the article?
"According to Rich, his rifle is just a shell of a Hatsan 135. He has completely remanufactured the powerplant with custom parts that are too exotic to explain. It uses a gas spring, but that’s as close as it gets to the stock rifle. He added a custom TJ barrel, after discovering that his new powerplant benefited by more length."
Yeah, that all sounds awesome but it's not a Hatsan Mod135 any more! Apples vs Oranges comparison.
"Theoretically" the ideal length barrel for each caliber should get all calibers to shoot at 34 fpe. I'd EXPECT the 177 and probably the 22 to gain a few fpe with the longer ~17.7" (YES, I measured it!) barrel on the Mod135 non-QE version. The 25 caliber is already rated at 34 fpe so like the 30 cal any increase in barrel length probably won't provide any significant fpe gain.
Having speculated that longer barrels are better for the 177 and 22, I DON'T see any EVIDENCE of that on my Mod135 Spring 177 17.7" barrel rifle! It's best performance is just under 28 fpe. The Hatsan engineers could probably give a precise explanation of why this happens due to increased barrel/rifling friction as a function of pellet circumference and an inverse cube-root pellet cross sectional area. But then they would have to kill us for knowing their trade secrets. ;D
Please feel free to experiment any way you want. I'm not trying to stop you. Just trying to clarify some real numbers that we currently see. I'd be very interested in reading about your results. The reproducible data that you gather will either prove or disprove your theory. There is no right or wrong here. "Observe, hypothesize, experiment, repeat" is the SCIENTIFIC METHOD and how we all gain knowledge.
Regardless of the results, you should enjoy the journey. Best wishes.
edit... corrected 3.4% swept volume difference to 7%
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Longer barrels should have less energy. The barrel becomes part of the swept volume. Pressure is only received when pellet leaves the barrel. Longer barrel reduces the pressure behind the pellet. You want the pellet to leave the barrel at the same time as the piston is coming to a stop. If the pellet is late leaving you have piston bounce. If the pellet is early leaving you have piston slam. Relatively easy to calculate the potential energy in a spring. In a gas ram????? :-\
Anyway, do it and let us know the results. If you want to shoot .30 pellets you probably should be going to PCP's anyway.
-Y
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Thanks for the info Yogi and Mikey! You guys are obviously very knowledgeable about springer design in general and these guns in particular and I appreciate you taking the time to explain this . To be clear, I just got a 135QE in .22 cal, but I have no intention of ever changing the barrel or even looking for more power... it is plenty of gun as it is, and I'm more interested in accuracy than speed anyway. I do love tinkering (and reading about tinkering) however, and I found this thread and the attached article both interesting. Now I know even more so thanks!
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This is a really interesting thread (yes, I know i'm kicking an old thread, but hopefully everyone's subscribed to the thread).
Did anyone do any comparisons ? preferably with pellet weight, FPS/m/s ? Precision ?
I'm buying a 125/130/135 .22 for up to 100m/110 yards shooting, can't just decide which one.
I've already got a BT65RB PCP for 200m ±50m shooting.
Cheers,
Pop
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Different gun, but I cut the barrel on my RWS 3500 (gas piston magnum) from 19.6", down to 16".
Velocity rose from 825 fps up to 860 fps (Crosman 14.3gr), and accuracy improved (less barrel time?).