The Stevens 311 will be somewhere around 6# 5 oz. with 26" barrels, the Yildiz much more of a "wand" at 4# 13 oz. with 28" barrels. Big difference. But, ............... you
MUST consider the RECOIL!!!
SRH
This description jives with all the Stevens 410's I've ever seen. The frames are 12 gauge frames and are so wide that they have no side balls. The barrels sit on a platform to raise them up high enough to align with firing pins. Jim I'd love to see photos of the Stevens 410 you're describing.

Here's a picture of one I found on the internet.