Where's my power gone?

[Bazz]

Hi all, so I recently stripped down my new rifle, it's nothing fancy a Chinese made Diana Two Fifty, and gave it a thorough de-grease and re-lube with decent moly grease, I also gave the piston a light polishing because it felt pretty rough, and it was a light polishing, just by hand with 1000grit wet and dry light pressure and then a once over with autosol. Re- assembly was fine, nothing was forced into place, no bits left over and now it feels a bit smoother in the firing.

However, I took some chrono readings before and it was averaging around 9 - 9.5 ft/lbs depending on pellet, not great but cheap rifle, I expected this to go up slightly with a better lubed and smoother moving piston however it has dropped significantly now averaging 5.5 ft/lbs

Any ideas to exactly what I have upped?

Thanks.

 

[blklab]

Was it dieseling before you stripped it?

 

[Bazz]

Not that I'm aware of no, and it had fired probably 300 or so shots from new, so I imagine it would have settled down if it had been.

Also these readings were taken after 70-80 shots post strip down, so again hopefully enough to settle down again.