Different fps for extreme accuracy same barrel Different guns

[mubhaur]

I arranged an original RAW HM1000X .25 60 ftlb polygonal barrel. In original RAW it was 1" at 100 yards with 34gr JSB at 910 fps.

After machining the same barrel for my fx Impact, the barrel is still very accurate but now it gives extreme accuracy at 950fps with same 34gr JSB .25 pellets. 

Is it due to change of harmonics or its something else ?

Regards, 

Umair Bhaur 

 

[bandg]

Different harmonics? Different amount of residual air exiting the muzzle? How you were holding your mouth while shooting? Not trying to be snide but this seems to the be standard for air gun shooting-figuring out definitively WHY a specific system behaves the way it does in comparison to another different but very similar system. Change to a different run of pellets and it might be different again.

 

[mubhaur]

Different harmonics? Different amount of residual air exiting the muzzle? How you were holding your mouth while shooting? Not trying to be snide but this seems to the be standard for air gun shooting-figuring out definitively WHY a specific system behaves the way it does in comparison to another different but very similar system. Change to a different run of pellets and it might be different again.

Nice. Let's see.

 

[Long_Gun_Dallas]

The barrel is mounted differently for sure. That will affect harmonics. Of course valve characteristics are a factor 

 

[Vetmx]

Yep, I have 3 different TJ .25 barrels on 3 different guns. Nothing is the same except the diameter of slug they prefer. I believe the biggest factor is how the air is delivered. Next is seating depth, then barrel harmonics.