Most copper is Hard Drawn as supplied. I have machined more than my share to make EDM electrodes. The answer is to buy free cutting copper that has some sulphur added, another advantage is that it does not bend when the skin is cut like the HD stuff. When I was working in the mould making industry I bought the free cutting copper from EDM suppliers. Here in the midlands I used two companies Erodex and Graphite technologies.
Depending on the final use of the copper it should be fine but you would need to check spec if making a boiler.
The two stockists above sell in 12" lengths but like all copper it does not come cheap. If you form grind it use plenty of tallow on the wheel, for general machining cut dry or use a little soluble oil from a washing up liquid bottle.