is one better than the other?

416 is easier to machine than 410, because it is not as hard. The only 410 barrels I have seen were substantially more expensive than the 416 barrels. I would dispute that 410 is a lesser grade of steel, from what I have read 410 is the better grade, in terms of hardness and corrosion resistance, because more sulphur is added to 416 to make it more malleable. But again 410 is much more difficult to machine. However it pays dividends because 410 Stainless is more weldable, formable and corrosion resistant than 416.

Grade 416 has the highest machinability of any stainless steel, at about 85% of that of a free-machining carbon steel. As for most other free-machining stainless steels the improvement in machinability is achieved by addition of sulphur which forms manganese sulphide inclusions; this sulphur addition also lowers the corrosion resistance, weldability and formability to below that of its non-free machining equivalent Grade 410.

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