Let’s be clear about this gun test right now. What I’m doing – putting a variety of AR-15s through five torture tests – you should not do. It is/was hazardous, abusive, potentially very expensive, and more than just a bit crazy. I took thousands of dollars worth of fine machinery and worked very hard to see just how far I could push it before something gave up. If, even after I recount this gun test and tell you to not do the same, you go and do it, don’t blame me. I told ya not to do it.
Gun Test #1: Buried Alive
I took each AR-15, loaded it, chambered a round, closed the ejection port door, dropped it on the ground and shoveled topsoil over it. I then picked it up, fired five rounds, left the ejection port door open, put it on Safe, dropped, shoveled and repeated.
In shoveling, I made certain to get a full shovel of dirt right onto the open ejection port (bolt closed on a loaded round) and to put two shovelfuls onto the forearm, to work their way down to the piston system, if any. Just to be thorough, I shoveled dirt onto the handguards of the DI-driven rifles, but I also did so with the full realization that it was pointless with them.
When empty, I changed magazines, left the ejection port door open and continued. Once I had gone through all three magazines I moved on to the next rifle.
AR-15 Torture Test Result: This proved spectacularly unimpressive, so I moved on to Test Two.
Gun Test #2: Sand Trap
My hope was that the sand would be a lot more abusive to the systems than the topsoil. My hopes for this AR-15 torture test proved to be unwarranted. They all shrugged off the sand just as they had the topsoil. Oh, there were differences.
For one, sand, propelled by the muzzle blast, is a lot harder and sharper than topsoil. I got to the point where I could tell you, just from the impact on my hands and arms, if a rifle had been dosed with topsoil or had been given a sand bath. And any rifle with a muzzle brake on it was a lot worse than just an A2 flash hider.
Also, the sand in the piston systems, I think, was pumping granules into the air. Not much, and it certainly wasn’t hindering the piston function, but I could feel sand on my hands coming from a direction not of the muzzle.
A brief aside here, on muzzle control and testing. Even though I was dropping rifles on the ground, I was careful to not let the muzzle get packed with dirt or sand. Well, careful at first. After a few “Oh what the heck, let’s see what happens” moments, I didn’t bother trying to keep dirt or sand out of the flash hider. What led me to that was a few episodes of dirt in the muzzle. In the process of carefully poking it out with a stick, I discovered that the dirt was only in the flash hider itself, and not down the bore. So, the next time the flash hider got dirt in it was when I said, “What the heck, let’s see….,” and pulled the trigger.
AR-15 Torture Test Result: Puff of dirt, bullet hits backstop, no apparent damage. So, while I didn’t go out of my way to be careful nor to deliberately pack dirt in the end, I didn’t worry about clumps of dirt or sand that I could see in the flash hider.