Fairly common. I see all my different size pellets from different guns from time to time. My .177 Wildcat at 950 fps is easily visible.
Also, if you see your pellet curling or making some weird movement like a knuckleball or hooking in from the right or left, then you have either clipping or the pellet is too fast. That spells "inaccurate". If you watched that little video of someone's .30, look at how the pellet flies. It should have a slight up then down arc. Every pellet should fly just like that. Anything else means the pellet has destabilized and it can go anywhere other than where you aim.
Crusher
ps. In some cases on a very windy day, you may see the pellet arc sideways a little. But that is not the norm. And the sideways arc should still be consistent to the wind.