Who knows much about the 356 winchester... Useful/not useful? The gun I am looking at is in a lever action... Can I still get bullets (factory)? Why don't I hear a lot about it? What is the range like? Any info would be great.

I am a lever gun fan and reloader so I would buy it in a heart beat if it was in good shape.
Ammo can be a problem to find, although I have seen it but I don't think anyone has made a run in a long time.
The .307 and .356 are basically rimmed .308 cases with the .356 being necked up to .358. They are not loaded quite as hot as a .358 because most lever guns that were chambered for them won't take the pressure.
Because you would have to use a round nose bullet and since it's a lever action it might do well at 200yrds. but I would not push it past 150 at most. JMO

It is a 308 case necked up to 35 caliber. I think they added a rim to the case. It came out in Winchesters Big Bore along with the same case called the 307 Winchester. They also chambered it in the 375 Winchester. The sales never came about and I think only the 307 remains if even it does. I have a hundred or so new brass for the 356 if anyone is interested. If I recall they used a 358 caliber bullet which shoul still be available. I think Marlin chambered some of these and I know they chambered the 375 Winchester. It was an attept to breath some new life into the Winchester lever guns. For short range woods hunting they were a good gun but suffered from the same problem all tubular magazine guns face. The inability to handle pointed bullets. Sorry I don't recall an awful lot about them I had a 375 and a 307. I had a 356 ordered thus the brass that I have. I changed my mind and never bought the 356. There will be more knowledgeable people who can tell you more.

The 307 and the 356 are pretty much a 308 and a 358 with a rim ..

Yeah they're useful. A small improvement over the 35 rem. I think.

Anyway, a good woods gun out to 200. Ammo will be harder to find than the 35 rem though. If you reload, snatch it up.