Chain cutting speed

[Poundcake]

I am going to get some Stihl chain that is the RS in the .325 to start. I plan on opening my muffler this week also. Is there a figure as to how much I should open it up. I did take it apart this evening and took note there is a "baffle" welded to the rear part of the muffler. Should that be removed also.
Thanks guys there's a ton of saw info here.

 

[stihltech]

teeth

I still remember the customer that brought in an 031 with 404 chain and a 24 inch bar. He had moved from the west coast to WNY. He said iy worked great in softwood, but is soon had a 20 inch 3/8 bar on it.