Feb 13 2012
There is a great debate about using steel cased cartridges in the gun world. Everyone seems to have their opinion on whether or not steel cased ammo is the way to go. Personal preferances are best made when based on facts and not the opinions of others.What I want to share with you are the facts, not my opinion.
Please note, some guns are designed to have steel cased ammo run through them, such as the AK-47, many AR-15s, and the SKS. This article is about the use of steel casings in guns that are NOT designed to tolerate it.
Lets start with the stats:
Barrels are usually manufactured from stainless steel which has *Rockwell hardness value of B95. Mild steel casings have a Rockwell hardness value of about B71. Brass casings have a Rockwell hardness value of B58.
*The Rockwell Hardness test is a hardness measurement based on the net increase in depth of impression as a load is applied. Hardness numbers have no units and are commonly given in the R, L, M, E and K scales. The higher the number in each of the scales means the harder the material.
Hardness has been variously defined as resistance to local penetration, scratching, machining, wear or abrasion, and yielding. The multiplicity of definitions, and corresponding multiplicity of hardness measuring instruments, together with the lack of a fundamental definition, indicates that hardness may not be a fundamental property of a material, but rather a composite one including yield strength, work hardening, true tensile strength, modulus of elasticity, and others. In the Rockwell method of hardness testing, the depth of penetration of an indenter under certain arbitrary test conditions is determined. The indenter may either be a steel ball of some specified diameter or a spherical diamond-tipped cone of 120° angle and 0.2 mm tip radius, called Brale. The type of indenter and the test load determine the hardness scale(A, B, C, etc).
– 2001 by CALCE and the University of Maryland
When you compare the hardness of mild steel versus brass, the hardness value is almost 50% more for mild steel. This would translate to about 50% more wear on stainless steel components when using mild steel cased cartridges. These components would include: the barrel/ chamber assembly, extractor, slide and ejector. The result is premature wear on the feed ramp, the chamber dimensions and slide.
If the designed lifespan of your steel gun is 10,000 rounds, then you could potentially reduce the lifespan to 7,500 rounds based upon the almost 50% wear rate.
Additionally, most gun manufacturers will void your warranty if you shoot steel cased ammunition through your gun.