For my Mrod, replaced the 20" LW barrel with 24" LW with the same specs and got a 60+ fps increase without any adjustments.
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Barrel length and FPS?s
- Thread starter igolfat8
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How much air? A small chance you are limited in air volume.
If your gun is regulated you may not have enough air to accelerate the pellet the length of the barrel.
I ran into that on a regulated .25 AF Condor. Put a 24" barrel on and FPS was virtually the same as 18" barrel. Changed regulator to one with 50cc plenum, FPS increased over 100FPS.
If your gun is regulated you may not have enough air to accelerate the pellet the length of the barrel.
I ran into that on a regulated .25 AF Condor. Put a 24" barrel on and FPS was virtually the same as 18" barrel. Changed regulator to one with 50cc plenum, FPS increased over 100FPS.
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Looks like milage will vary, my mrod was regulated @ 132 bar and pretty much doesn't have a plenum, maybe 15cc that came with the HUMA kit and then maybe another 5cc with the Hill valve.
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On AF there was virtually no plenum.
So all I was getting with a fixed regulator was from the reg to the tophat.
Since those early days I've experimented and found 3x-4x barrel volume is good, 5x-6x is where the gains flatten.
.25 cal 24" barrel is almost 20cc
So optimum plenum should be 60-100cc.
Objective is to keep the pellet accelerating the length of the barrel.
When air runs out acceleration ceases.
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I did test velocity in my condors one with 27.5" and the other 33.5" I was getting more speed with the shorter barrel at 3,100 psi with a 70gram hammer than with the 33.5" at 3,600 psi and a 116grams hammer .. so between 28 n 29" long is the max length good for .22 . Above that you loose speed. I have seen similar test in the PB world but didn't think it would apply to airguns but it does.
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Friction overcomes energy?
Are they regulated? If so what kind of plenum do you have?
.22 27.5 is 17cc barrel volume
.22 33.5 is 21cc barrel volume
27.5 would need 51cc minimum plenum
33.5 would need 63cc minimum plenum
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I'm confused, the bottle is attached to the regulator, regulator attached to tophat, correct?
Plenum is the space between the regulator and the tophat.
The fat part on the Huben Max-ATH
Plenum is the space between the regulator and the tophat.
The fat part on the Huben Max-ATH
Huben Power Airgun Regulator Airforce condor Regulator
Thank you Air Shootist for the video. Huben Power 50CC Cricket-MAX-ATH Regulator This regulator can be installed in most airguns which use standard airtank with thread M18x1.5. Listed below are some of the M18*1.5 airguns. （In fact, it is not limited to these models airguns.） AirForce...
shop.hubenpower.com
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I'm confused, the bottle is attached to the regulator, regulator attached to tophat, correct?
Plenum is the space between the regulator and the tophat.
The fat part on the Huben Max-ATH
Huben Power Airgun Regulator Airforce condor Regulator
Thank you Air Shootist for the video. Huben Power 50CC Cricket-MAX-ATH Regulator This regulator can be installed in most airguns which use standard airtank with thread M18x1.5. Listed below are some of the M18*1.5 airguns. （In fact, it is not limited to these models airguns.） AirForce...shop.hubenpower.com
Or the tube above the bottle 125cc plenum.
Regulator is the gauge above the neck of the bottle.
Bottle->U adapter->Regulator->125cc Plenum->Tophat
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About 15 or so yrs ago , i was playing with co2 Crosman 2240 & 2250's i was told that longer barrels = up to 10 fps, per inch ,i was installing 18'' barrels & getting more power, & then started using what i called a hot valve , & got way more power, but just with the 18 inch barrel made a big difference..
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Your conclusion was based on a faulty comparison.
Use the same airgun and keep all settings the same, including pressure and hammer weight. Same projectile. Swap barrels for the comparison. Compare the 27.5” barrel with 33.5” barrel.
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For me not a faulty comparison.. the 27.5 has a TalonP valve and a lighter hammer..the other has a .257 no return spring Doug valve n a heavy spring , 116grams hammer + 5 additional inches of barrel by our basic knowledge it was supposed to be on average 10fps faster than the short barrel, but it wasn't . I installed the TalonP valve on the 33.5" long barrel and it was going even slower.. so 33.5 is way to long for.. 22 caliber no valve flows more air at 36000psi than the Doug valve.. same barrel length in 257 I could push 100gr at 1020 in preload one .. so the problem is how much air could be push by a .22 caliber hole .. n benefit of it apparently not enough to take advantage of 33" of barrel in .22 ..
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Where it falls apart is what volume of air is pushing the pellet? Does the volume fail to maintain pressure the length of the barrel.
If the pressure drops to below acceleration pressure at 20 inches then you effectively have a 20 inch barrel not a 27.5. The last 7.5 inches just spin the pellet and friction may slow the pellet.
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AT 29 it still pushing the 64gr bullet .. it falls apart after 29 .. will cut one of them to 30.5 just to see where it goes.. I just posted what happened in a test . really was expecting to be supersonic at 33.5 but it didn't.. kept in mind than a 64gr bullet in 22 is almost 3/4" long as long as 85gr . 257 bullet
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Pellet weight is more a function of initial pressure. Heavier pellet takes more energy to accelerate from rest. That damn Newton and his laws. Continued acceleration takes more energy too but the question still remains at what point does the pressure on the pellet drop below the energy required for acceleration.
High starting pressure only gets you part of the way.
These two can give the same FPS/FPE
High pressure no plenum: high initial accel but ceases acceleration soon.
Lower Pressure w plenum: Pellet accelerates for a longer period
You get more shots with the plenum.
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