Wild Knight
ArboristSite Guru
.325 9-pin is one of the recommended sizes for the MS361 (in the user manual etc), and probably the fastest one with short bars and small wood.
The others are 7- and 8-pin 3/8".
Outer diameter/gearing is very close to the same as 8-pin 3/8".
Is it possible to run an 18" .325 on the 361, then switch over to 3/8" on the 25" ?