Hey guys seeking some sharpening advice for my ms261 and my ms440. The only sharpening I have done is with a file (with no holder) and I butchered up my first chain. The saw cuts super slanted cause I must have filed one side more than the other. So here are my questions 1) do the ms261 and ms440 take the same Sized file? 2) I found a bar mount for 30 dollars on amazon would you guys recommend that? Any advice is greatly appreciated.