That sprocket is past due for changing.
I have three chains for each saw...every time a saw gets cleaned, first I sharpen the chain, take it off, clean and flip bar etc. etc...then when it goes back together one of the other chains goes on and the just sharpened one goes in the bottle for next time...that way the three chains are rotated for each sprocket and bar.
The rim or spur sprocket then 'sees' three chains and wears a little bit for each one, so there are tolerances for each chain. If I only ran one chain until it was no more good, then put on a brand new one, all the wear marks now present in the sprocket are for the old chain, so the new one will have to force new wear marks or itself be forced (more likely) to run in the existing wear pattern, and thus as Magnus and Willard say, the new chain cops a beating!
Think about it too, if you have deep grooves on the sprocket, the drive link can even 'bottom out' adding friction and wear, not to mention the tie straps, especially below the rivets... just not good all around.
The way to know if your nose sprocket is worn is if all the sprocket teeth tips are triangular and come to a sharp point. Usually the sprocket teeth are slightly flattened at the tip, sharp pointy ones means the metal has been worn away from each side. More room for slop and movement of the drive links, more wear and tear.