REMINGTON 300 WIN MAG AMMO FUNDAMENTALS EXPLAINED

I would like to find a barrel that may be to get a wingmaster only? What length will get me to authentic and they are there more time barrels readily available? To who need to I turn Moreover ebay?If Remington 870 Wingmaster allows me to shoot some clays (seriously on the leisure level) and some slugs (seldom) then I greater keep my fingers crossed