Let’s get price out of your way first. As metal shooting targets are sold by the pound, the thicker the steel, the more that you are paying for the exact same target surface location. The thicker the target, the additional weight you will need to move it and in the event should you do not possess the option of obtaining a permanent kind to utilize, then you will really need to use a sufficiently heavy stand to hold the target for you personally to shoot. As a result, it behooves you make use of the thinnest steel that should safely and reliably deal with your long-term shooting desires.
Secondly, a discussion of contemporary industrial steel. The common steel you will probably locate lying about is known as Mild Steel, or A36. It is actually quickly welded, formed, and drilled. It usually features a Brinell Scale hardness of 120-180. It can be the backbone of modern day shooting, and may be purchased inside your nearby hardware shop, picked up as scrap from neighborhood shops, and salvaged from a variety of sources. It’s also fully unsuitable for use as a secure, extended lasting firearms target for something besides little caliber, comparatively low velocity, rimfire platforms for example the 22LR and 17HMR.
In thicknesses much less than 3/8”, modern day handgun calibers including 9x19mm, 40S&W, and 45 ACP will leave dimples, rapidly causing an unsafe shooting surface on mild steel. Magnum handgun calibers will leave deep dents, and may even penetrate the comparatively soft mild steel. At 100 yards, centerfire rifle calibers such 308 will fully penetrate 1/2” mild steel, and lesser calibers will leave deep craters.
To get enough mild steel to stop rifle rounds at 100 yards, you’re looking at about 40 pounds of steel per square foot (one inch thick), and a surface that should rapidly be a moonscape of jagged edges, pits, and ricochet inducing odd angles. As I stated, mild steel is absolutely unsuitable as firearm metal shooting targets.
Abrasion Resistant (AR) steel comes in different hardness (usually 400 and 500, Brinell Scale) and thicknesses. AR400 and AR500 steel is commonly used as wear plate on construction equipment, dump trucks, mining process equipment, and farm equipment. It can be, effectively, exactly the same thing as mild steel, but with better quality control, and a heat tempering process that hardens the steel through its entire cross section. AR400 is generally significantly less expensive than AR500, and is for that reason a lot more commonly available. It can be, alas, too soft to deal with centerfire rifles at 100 yards, pitting visibly.
Many manufacturers offer targets in ¼” AR400, and 3/8”, ½” and 1” AR500. They possess the capacity to design and produce targets up to 60×120” as a continuous piece. They can make custom metal shooting targets of virtually any size, shape and thickness. Our current product line includes both static, gong style targets and kinetically activated “reactive” targets.