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Chronograph Results

Started by Gareth, May 19, 2013, 08:38:50 PM

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Gareth

Barrel length velocity comparison test using RWS Meisterkugeln wadcutter 14 grain pellets:
Temperature: 74 degrees
Humidity: 35%
Elevation: 587'
Wind: 5-10mph (Test conducted within enclosed patio with no roof.)
Range from chronograph: 7'
Each test was started with a clean bore and new CO2 cartridge. The first three shots were discounted each time due to erratic velocity results, which seem to be mainly due to new cartridge break-in.
2300KT (10" barrel) Average velocity: 480fps
2400KT (14" barrel) Average velocity: 560fps
Tech Force M78 (22" barrel) Average velocity: 500fps

http://airgun-academy.pyramydair.com/blog/tag/barrel-length/


Brent

#1
Cool... Thanks!! :-*
What is the average shot count that you are getting out of each gun? Basically, are they the same basic internals, and is that extra 80 fps on the 2400 only from the extra 4 inches of barrel length?

Gareth

Quote from: Brent on May 19, 2013, 10:49:56 PM
Cool... Thanks!! :-*
What is the average shot count that you are getting out of each gun? Basically, are they the same basic internals, and is that extra 80 fps on the 2400 only from the extra 4 inches of barrel length?

20-30 full power loads from all three before velocity really begins to drop off.
The 2300 and 2400 are basically the same, of course. But the TF 78 uses two 12G CO2 cylinders that usually deplete between 40-50 shots. Accuracy is superb, however.
For comparison, the .22LR high speed cartridge attains its highest velocity in a 16" barrel, due to the diminutive powder charge, no doubt. Due to its inherent operating pressure, I think this is why CO2 gas peaks out in a barrel around fifteen inches long.

http://www.pyramydair.com/article/What_About_CO2_December_2003/6



Brent

Thanks... good info on the 22... didn't know that.

So I guess it is safe to say then that the extra 80 fps between the 2300 and the 2400... is in the extra 4 inches of barrel? Basically you are gaining it there.

Not 100% sure, but I think the consensus is that 18" is the optimum length for a co2 barrel. Wonder if another 4 inches would gain you another 80 fps, or more? I wouldn't think the gain is linear to each inch, but rather proportional to efficiency gains overall.

Just talking out load is all, to see if someone with more experience in this jumps in.

Gareth

Quote from: Brent on May 20, 2013, 07:03:20 AM
Thanks... good info on the 22... didn't know that.

So I guess it is safe to say then that the extra 80 fps between the 2300 and the 2400... is in the extra 4 inches of barrel? Basically you are gaining it there.

Not 100% sure, but I think the consensus is that 18" is the optimum length for a co2 barrel. Wonder if another 4 inches would gain you another 80 fps, or more? I wouldn't think the gain is linear to each inch, but rather proportional to efficiency gains overall.

Just talking out load is all, to see if someone with more experience in this jumps in.

Yes. Someone with a chronograph, a CO2 rifle with an 18" barrel, and a pack of RWS Meisterkugeln pellets.  ;)