Interesting comments, I think the main question has already been addressed as to the pros and cons of Nickel plated brass. However reading through I did see a few errors I would like to address. I should start by saying that I am an Aeronautical engineer, not a materials engineer, but I do have a generalized understanding of materials and their properties.
Electroless nickel plating has a Rockwell C hardness of up to RC-55. This is much harder than mild steel and harder than many tool steels.
This may be untrue when applying to the nickel plating of cartridges, Most cartridges are normalized, this means they are heat treated by heating then steadily cooling to release internal stress. This process would put its hardness at the lower end of the range. Also many reloading dies are made of Tungsten carbide (which has a Rockwell hardness of Rc 75 – Rc 80 ) Regardless a smart reloader should debur the inside of the case mouth with a brush prior to loading. According to the Mil-HDBK-5 (Mil handbook, which we use to define metal properties in engineering) has the hardness of each. There is a vast range of harness depending upon how the steel was heat treated. I
don't know what type of heat treatment they use so I will not try and “guess”. But based on the application, both would be at the lower end of the hardness spectrum. Most rifle barrels are made from either AISI 4140 (carbon steel) or AISI 416 (stainless steel) The hardness according to Mil-HDBK-5 is as follows:
AISI 4140 : Rb 93 - Rc 50
AISI 416 : Rb 85 - Rc 39
Electroless nickel is added mainly for corrosion resistance, but also because of its lower friction coefficient to increase reliability from cycling. it does not need to be hardened so it would be at the lower end of the spectrum. Most cartridges are "normalized" meaning that they are heat treated with low heat and long term cooling, also reducing hardness, but increasing ductility.
From Mil-HDBK-5:
Normalized Electroless Nickel : Rc 49
You could also make the argument for the potential of increased bolt thrust. From my experience with nickel cases it seemed to have less stretch. In my mind I figured a brass case would stretch out and grab the chamber walls better than a stiffer nickel plated case. If this is the case it would cause more stress on the bolt lugs than necessary.
This is not necessary true because the pressure inside the cartridge is still enough to “fire form” the cartridge. The difference would be that it would occur at a higher pressure than the brass case. Internal pressure should peak at the same for both cartridges (brass and nickel plated brass)
Also, once you fire the case, the rougher nickel on the inside of the case is heat treated. I don't know if anyone's ever done a test on the hardness of the microscopic particles after firing, but I'd bet they're harder than the barrel.
This is incorrect. Heat treatment increases hardness of a metal by changing the crystalline structure of the metal. It is changed depending on how hot, how long, and how fast you cool the metal. The heat transfer from firing a bullet is not enough to heat the metal up to a temperature where it would change the crystalline structure. So no it does not heat treat the case.
I doubt a piece of the nickel would do any damage to the barrel for a few reasons: 1. A piece of any significant size would just scratch the copper jacket of the bullet, anything small enough to break off would most likely be so small that it would not do any significant damage. 2. The plating is so thin that it would most likely sheer of upon entering the barrel. Depending on the nickel used, it may be harder, but steel is stronger. But these are just guesses, as there are too many unknowns for me to form a solid answer.
For the original poster:
I like nickel cases for the following reasons:
- They don't corrode easily
- They allow me to distinguish between 2 loads of the same caliber (1 in brass and 1 in nickel-brass)
- They are easier to find at the range when picking up
- They look "cooler"
