Hence my suggestion of an Echo 590.People act like the mid-grade is just disposable junk but it’s not. I know the 044/440’s have a metal crankcase but I own clammy ‘s that are every bit as durable as mag cased saws, mileage wise.
That said, the size (power) difference between a 440 and a 311 is quite substantial, but for someone doing a lot of firewood gathering and not needing the best power to weight ratio, the 311 will do fine. However, I think Stihls are overpriced and I wouldn’t pay for a new 311 with the other 60cc options out there.
The Stihl 440 was a very good saw. Picking a solid used one is hit and miss. We tend to answer questions like this with what we want and with no regard to experience base of the OP's or their real needs.
I've heated mostly with firewood for close to 40 years, never had a saw bigger than a Stihl 036. Would I like a 440, 462 or 5ooi? Of course. I've never really needed one. The bit of extra time it sometimes takes vs. the money still in my account has made it a good tradeoff.