When the main alloying component is carbon, you have carbon steel, which comes in varying grades of low, medium, and high. Low-carbon steel, for example has 0.05% to 0.320% carbon; whereas medium contains from 0.3 to 0.59%.
The high-carbon steel possesses from 0.6 to 0.99%. There is actually an ultra-high degree that contains 1.0 to 2.0% of carbon content and would be tempered to the highest degree of hardness in this specific category of the blade.
All in all, the best quality steel, for hunting purposes, would contain at least 0.6%. This allows for both hardness and flexibility which can come in handy for many purposes related to hunting and also for easier maintenance.
You can read more about the steel quality of Mora knives here.
For the most part, carbon steel blades tend to cost less than their stainless steel counterparts, which is great news for any hunter. One example, the Mora Classic Number 2, which has a 4.2-inch blade, usually starts at about $15, but don’t mistake a low price for low quality.
These knives can be hardened to HRC 58-60, which is optimum sharpness at an affordable price, which is one reason why hunters prefer this type of knife. However, if cost is not the most important factor, other brands of carbon steel knives can run from $30 to $250, depending on what you need for your next trip.
As mentioned before, carbon steel knives are more flexible, and this trait makes it easier to sharpen. Since a carbon steel blade holds its sharpness longer than its stainless steel counterpart, it takes less time to repair and sharpen—yet another reason to take this type of knife on the next big hunt!
Every avid hunter has certain preferences from favorite locations to preferred equipment. Such is the case hunting knives, and here are a few reasons and advantages for choosing a carbon steel blade.
Any hunter knows that maintenance is vital, but a carbon knife can last for several decades when given the proper care. In turn, this is another great advantage for a hunter who utilizes carbon steel knives on a regular basis. They will definitely last.
Likewise, something important to remember is to wipe off the blade after each use, as it will rust over time if this is not done. Sometimes, they do stain, but this does not adversely affect its performance and eventually serves as outer protection for the blade.
So these are the main reasons why hunters prefer carbon steel knives. They cost less and are easier to sharpen and maintain, which means less time dealing with subprime gear.
This article on the truth about knives sums it up nicely. http://www.thetruthaboutknives.com/2013/09/knife-review-morakniv-bushcraft/
All prices are in AUD.