I doubt he’d be happy with a 25” .404, on 500i but this chap is running a 20” bar in iron bark and doesn’t seem to be causing it any issues - it’s ripping through easily, I guess it would be 3/8 pitch
No issues I see a few lol
The operator is pretty wild think he was going flat out showing how good his saw cuts, did ya see his hand get blown off the handlebar when the saw had a fast sudden push back needs to wrap his thumb under the handlebar a bit more.
Chain is too aggressive and or rakers too low saw was bogging bad slipping the clutch with the combination of operator going a bit to wild and whatever is going on with the chain gearing could be a factor in that as well.
Going off that vid it's not inspiring that it could pull .404 25inch bar buried long term reliably.
But I'd dismiss that vid its not a very good vid to gauge the performance of the saw.