Zoraki speeds

I just got my Zoraki Ultra 177 and it seems to be shooting a little slower than the numbers I've seen posted around here out the box. 8.4 grain JSB exacts around 295 fps with 1 pump, 440ish with 2 pumps, and high 400's with 3 pumps... 

It sounds like this is way off from what other people are experiencing, but I wanted to see what you're all seeing. I'm wondering if it just takes a while to warm up. I'm still pretty happy with these speeds I guess, and it's still accurate, but I was just expecting a little bit higher. thanks
 
Zoraki ultra .177 speed.

1 pump 406, 2. 531, 3.616, 4. 675 with jsb 8.4.
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