In recent years, the price of ammunition has shot through the roof. For people who enjoy going to the range and firing a lot of practice rounds, the cost of ammunition can be a huge problem. While it is possible to make your own ammunition to help cut down on the costs, doing so is not always feasible. Fortunately, one way to save money on ammo is to purchase inexpensive surplus ammo in bulk. However, surplus ammo tends to be corrosive. Here's what you need to know about corrosive military grade surplus ammo and how to clean your AR-15 and bolt carrier group effectively when using corrosive ammo.
Military Grade Surplus Ammo
The military surplus ammunition that you find in military surplus stores sometimes contains corrosive primers. This type of ammunition was reliable and allowed for long-term storage. In fact, it's the type of ammo that was used during WWII. However, they've since been phased out by the United States military and replaced with non-corrosive ammunition. Other nations have also started phasing out ammunition with corrosive primers though in more recent years. Because of these factors, military surplus stores often carry copious amounts of ammunition with corrosive primers.
Military grade ammunition uses the metric scale, whereas civilian ammunition uses the Imperial system. Regarding ammunition for your AR-15, the military grade replacement for the civilian .223 round is a 5.56mm round. These rounds are essentially the same. However, due to the corrosive qualities of the surplus rounds, you'll need to change the way you clean your AR-15 and the bolt carrier group.
Cleaning After Using Corrosive Ammo
Of course, you'll need to field strip your AR-15, which includes breaking down the Mil-Spec Nickel Boron bolt carrier group. Because of the small essential parts of the bolt carrier group, such as the retaining pin and the firing pin, it is crucial that you place the pieces directly onto a clean white towel so you can see each piece clearly.
Carefully rinse the entire rifle and each part of the bolt carrier group thoroughly with water, preferably hot. Do not use oil or carbon solvent until after you've rinsed the parts copiously with water. The reason for this is the corrosive primer of the surplus rounds leaves behind a trace of salt. Salt cannot be dissolved by oil. Salt can only be dissolved by water. After you've thoroughly rinsed all of the parts, allow it all to air dry before using oil or carbon solvent to finish cleaning as you normally would after firing non-corrosive rounds.