You can get brass from midway or Graffs for about $20/50 cases, and have been consistently available. Bullets are made by hornady, barnes and hawk in 180, 200, 220, and 250 grain flavors. I've found that the hornady are hit or miss, but I stock up when they are available (usually from graffs). I've also recently bought a mold to cast my own bullets from mountain molds. Factory ammo for the 348 goes for about $30-35/box US. I reload mine.

If I were you I wouldn't trade that rifle for anything. Nor would I rechamber it--it will ruin the (high) value. You have what is arguably the ultimate lever action rifle (some may argue the winchester 1886 is better). I bought a browning reproduction 71 and consider it to be the finest rifle I own (I admittedly don't own any fancy guns). Original winchester 71s have been going for $700 and up--mostly up here in the US. If yours is in good condition it may well be worth $1000 or more, particularly if it's the delux model.

Get into reloading for your classic lever, you'll never regret it.

So I guess when I found my brass for 5c a piece canadian,I should jump for joy.And to anyone who would turn an orig. model 71 into anything else,I say BUTCHER.There are lots of anything elses out there without butchering these old beuties.The next thing we'll be reading is were have all the orig 71's gone.