New PDI barrel increased my FPS by 30fps, is this normal? - Airsoft Sniper Forum

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Old 11-17-2019, 03:51 AM   #1
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New PDI barrel increased my FPS by 30fps, is this normal?

I replaced my maple leaf crazy jet barrel from a 6.04 x 428mm barrel. To a PDI 6.05 x 430mm.

I bought a new m170 spring and started cutting and testing my fps. 580 to start, after several cuts I hit 540/550 fps. It's same lengh as my current one which I know is 520.

My old fps with an m170 action army spring cut was 517-522. Now it's 540-550.

Is this normal for a wide bore and not TBB? I feel like I just wasted $15 in a spring...
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Last edited by plasticnoob; 11-17-2019 at 03:54 AM.
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Old 11-17-2019, 07:09 AM   #2
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05 is not a widebore. Its still classified as a tightbore. (Anything under 08 is tight generally.) ML barrels inner finish is not all that great and the collar could be off some causing interference.

Could also be the spring. The spring could be a little stronger then normal.
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Old 11-17-2019, 07:45 AM   #3
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Changing the barrel can very well mean 30FPS difference, but I believe the spring is making the difference in this case. Springs are known to settle down with some use, so even if you have cut the new one to the exact same length of the old one, they can produce different FPS.

Instead of guessing, I'd throw in the old spring and check the power there, to have a direct comparison
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Old 11-17-2019, 12:51 PM   #4
1tonne   1tonne is offline
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Don't cut too much off of it otherwise when it does shrink, it will bounce around in your cylinder and can cause issues
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Old 12-09-2019, 12:17 PM   #5
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Yes. This is normal.
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