How to choose the correct steel for your shooting needs
Or: Why shouldn’t I just get the thickest steel plate I can find and use it for all my shooting?
Let’s get cost out of the way first. As steel is ultimately sold by the pound, the thicker the steel, the more you are paying for the same target surface area. The thicker the target, the more weight you have to move to and from the range if you don’t have the luxury of having a permanent range to use, and you’ll need to use a sufficiently heavy stand to hold the target for you to shoot. Therefore, it behooves you use the thinnest steel that will safely and reliably handle your long term shooting needs.
Secondly, a discussion of modern commercial steel. The typical steel you’ll likely find laying around is referred to as Mild Steel, or A36. It is easily welded, cut, formed, and drilled. It has a Brinell Scale hardness of 120-180, typically. It is the backbone of modern society, and can be bought in your local hardware store, picked up as scrap from local shops, and salvaged from various sources. It is also completely unsuitable for use as a safe, long lasting firearms target for anything other than small caliber, relatively low velocity, rimfire platforms such as the 22LR and 17HMR.
In thicknesses less than 3/8”, modern handgun calibers such as 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 relatively 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 will rapidly be a moonscape of jagged edges, pits, and ricochet inducing odd angles. As I stated, mild steel is completely unsuitable as a firearm target .
Abrasion Resistant (AR) steel comes in various hardness (typically 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 is, effectively, 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 less expensive than AR500, and is therefore more commonly available. It is, alas, too soft to handle centerfire rifles at 100 yards, pitting visibly.
3/8” AR500, on the other hand, will readily stop non-magnum rifle calibers at 100 yards with little to no visible damage to the steel. Happily, for our purposes, AR500 plate can take a real pounding.
At 200-300 yards, 3/8” AR500 is sufficient to stop magnum rifle calibers without damage. It is suitable for all standard magnum and non-magnum handgun calibers at 12 yards (including 500 S&W, with minor crushing of the plate surface and your hands), shotgun slugs at 50 yards, non-magnum rifle calibers at 100 yards, and magnum rifle calibers at 200-300 yards. Simply put, 3/8” AR500 will do the job for most shooters out there.
A quick diversion back AR400, which I so callously discarded as too soft. While 3/8” mild steel is unsuitable and weighs 15 pounds per square foot, it turns out that relatively inexpensive ¼” AR400 steel is useful. ¼” AR400 will readily stop standard handgun calibers such as 9x19mm, 40S&W, and 45 ACP, and is only 10 pounds per square foot. For non-magnum pistol shooters, who will never have a rifle on their range or are just getting into shooting steel, ¼” AR400 is a very practical answer to the age old question of “what am I going to shoot at today that I don’t have to clean up?”
So why would you ever buy ½” AR500 or 1” AR500 steel? For the average shooter, it is overkill to go to ½” AR500, and nearly comical to go to 1” AR500. However, for those with limited distance on their range and magnum rifles, it is helpful to step up to ½” for magnum rifles at less than 200 yards. ½” AR500 will wear longer than 3/8” AR500, and it resists deformation from repeated impacts. These features of ½” AR500 make it useful for law enforcement, public and private ranges and clubs, and other high volume shooters. 1” AR500 is pretty much exclusively used for 50 BMG.
MOA Targets LLC offers targets in ¼” AR400, and 3/8”, ½” and 1” AR500. We have the capacity to design and produce targets up to 60×120” as a continuous piece. We can make custom targets of virtually any size, shape and thickness. Our current product line includes both static, gong style targets and kinetically activated “reactive” targets. Feel free to check out our product line at www.moatargets.com
Tl;dr- Here’s a flow chart