Shooting an old slow firing M-60 will cost you about $465.00 per minute at current bulk ammo prices. Shooting something more exotic like an MG-34 or 42 will easily cost you over double that. You will need a fairly sophisticated reloading setup to get the cost of ammo down to manageable levels plus some really deep pockets to lay hands on a shootin' iron with spares and accessories. Saw a tricked out M-60 with five spare barrels go for $35,000.00 but that was some years ago.