 |  | | | |  | |  |  | Is length important ?? |  | |  |  | |
 Posted: Sat Jan 09, 2010 10:27 am |
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| diipii |
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Is there an optimum length for a .22 airgun barrel ?
Does the pellet achieve max velocity inside the barrel. In which case extra barrel length only serves to slow the pellet.
Is optimum barrel length related to cylinder stroke ? I am wondering if a barrel any longer than the piston stroke is just a waist of metal.
I have also been wondering about the dimensions of the transfer port and it's effect on velocity especially it's diameter and shape.
Any views would be very much appreciated. |
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| Posted: Sat Jan 09, 2010 11:12 am |
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| donwalk |
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it's relative...
relative to how fast the pellet is driven in relation to the length of the barrel AND the pellet as well as rate of twist.
more power=longer barrel...GENERALLY SPEAKING...not a "rule" though.
i read somewhere that in .22 RIM FIRE, long rifle, that 16" was optimum length for the barrel. the Airforce SS series has a 12" barrel that produce some pretty high velocities. |
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never squat while wearing spurs...will rogers |
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| Posted: Sat Jan 09, 2010 12:53 pm |
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| broommaster2000 |
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When a barrel is to long, on a springer that is, it can decrease the pellet velocity, and since the pellet will remain in the gun longer, it can decrease accuracy.
This doesn't seem to apply to PCP rifles or CO2 rifles as much though.  |
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| Posted: Sat Jan 09, 2010 12:58 pm |
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| AirGunEric |
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Moved from other thread of the exact same question (plese DO NOT create multiple threads on the same issue):
| rsterne wrote: |
There will be an optimum length for a Springer barrel.... but it will depend on the power plant involved and the pellet weight.... every design will be different....
For PCP and CO2 guns it's the same thing.... but in the higher powered versions you are unlikely to find a barrel long enough, let alone too long.... 
Transfer ports are tricky.... too big and the piston will crash into the end of the chamber (just as in dry firing).... too small and you lose power.... I don't think anyone will give you a difinitive answer on that question.... too many variables.... 
Bob |
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| Posted: Sat Jan 09, 2010 4:12 pm |
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| kanyon |
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For a co2 & PCP the barrel lenght is dependent
on the amount of Co2 or air released by the valve
to get full benifit fro is exspantion...
PCP...air compressed at 3000psi will exspand
206 time when released...
Springers....the pellet reachs max speed within the
first 10" of it travel down the barrel So from that point on the pellet is being slowed by the drag in the barrel.....
I have cut my guns down to 12 to 14" barrels..
Pete |
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| Posted: Sat Jan 09, 2010 5:27 pm |
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| donwalk |
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| kanyon...is that springer barrels you've cut down? and if it is, which ones? you can PM me with a response if you would rather...i don't want to "hijack" this thread. |
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never squat while wearing spurs...will rogers |
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| | | | | | | | | Re: barrel length | | | | | |
| Posted: Sun Jan 10, 2010 12:30 am |
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| kanyon |
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| donwalk wrote: |
| kanyon...is that springer barrels you've cut down? and if it is, which ones? you can PM me with a response if you would rather...i don't want to "hijack" this thread. |
Hatsan mod 75
B 11
B 1 |
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| Posted: Sun Jan 10, 2010 5:50 pm |
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| SteveM |
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| broommaster2000 wrote: |
When a barrel is to long, on a springer that is, it can decrease the pellet velocity, and since the pellet will remain in the gun longer, it can decrease accuracy.
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Exactly. I would think that the trick to figuring out the ideal barrel length for a given spring rifle would be to determine the amount of travel of the pellet at the point where the air piston has reached the end of its stroke. Of course, the barrel should probably be just a bit longer to allow for the time it takes for the built up pressure to bleed down.
However, once the pressure has dropped off, more barrel means decreased velocity due to friction and more chance for a deflected shot due to shooter induced movement. The longer a pellet remains in the barrel, the more prone it is to being deflected by the shooter's 'flinch' or other movement. |
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