Good test. But wouldn't you just assume pellets would yield a bit more velocity?? You have considerably more surface area to ignite. So I would assume the "firing time" would also be slightly faster as well with pellets?? Wouldn't it??

More surface area would allow the powder to ignite faster. And faster in a smaller area will be hotter. And hotter would give slightly more pressure. Which yields higher fps.

Sounds to me like your findings are right on.

I would be more concerned about the accuracy.

I have not liked the pellets because you have to shoot that exact load. You can't change the charge(only slightly). And as stated above I have always been concerned about smashing the pellets. And smashing would also change the burn rate.

And after all burn rate is what we are really discussing here?? Right?? Tom.