Stihl changed the way they label their saws a few years back. What was the old 028 AV is now the 280. And what used to be the 036 is now the 360......and so on

I'd say that your saw is probably the 410, given the way they changed their labeling of the saws. But, they're is no 410 saw today.

They're is, however a 390 model which is 3.9 cubic inches or 69cc. And the 440 model is a 4.3 cubic inch, or 70cc.

If I had to guess, and I will, I'd say it's somewhere in the 4.0 cubic inch range. Maybe 59cc--64cc.

Here's a link to the Stihl site. Scroll down to the drop-down menu and select your saw.

http://www.stihlusa.com/chainsaws/

Hope this helps.