Reliability Testing the AK-47
I recently acquired a Romanian AK -- specifically, a WASR-10 retrofitted to accept standard AK magazines. I've heard all about the legendary reliability of the AK series of rifles, and I decided to find out just how true that reputation is. I couldn't find any results on the 'net of objective, repeatable reliability tests so I had no choice but to run my own test.
Most reliability "torture tests" I have seen focus on built-up residue from fired cartridges -- the experimenters simply run mag after mag through the rifle being tested until it stops working. Well, I can't afford to blow a couple thousand rounds (or more, if the legends are true) through this AK just to sate my curiosity on this issue. Besides, it seems to me that when rifles malfunction under stress, the cause is foreign gunk getting into the receiver, not just the buildup from fired cases. The real-world problems don't come after 1500 rounds of normal shooting, they come after you do a face-plant in a mud puddle and submerge your rifle in sloppy goo. Regular maintanence can prevent the buildup from being a problem -- but only a good rifle design can keep working with a lot of junk rattling around in its guts.
For my testing, I used both dirt and sand. I was going to use mud too, but when I went to perform the test, it was cold enough that my mud froze. I'll do that part of the test later when it gets warmer. The dirt I used was a fairly clay-ey, clumpy variety I took from a pile near a construction site. The sand was standard childrens' sand-box dry sand.
Anyway, here are my procedure and results:
To quantify the amount of foreign object contamination required to cause a serious rifle malfunction.
1) Put a handful of dirt into a conatiner of water, and let it sit while proceeding with the next steps. This will be used later on as sloppy mud.
2) Clean and lube the rifle as you normally would. If you don't make a habit of cleaning your rifle after each trip to the range, then leave it as-is.
3) Load the magazine to capacity.
4a) Open the action, and drop in 1/8 tsp of sand. Close the action and fire 5 rounds.
4b) If you get a malfunction, make a note of it and apply the standard clearance drill (tap-rack-bang or look-lock-drop-rack-rack-rack-tap-rack-bang). If the drill doesn't fix the problem, mark down the total amount of sand in the gun and go to step 5.
4c) Repeat steps 4a and 4b until the rifle totally chokes (can't be cleaned by a simple clearing drill).
5) Strip the rifle down and clean all the sand out of it.
6) Repeat steps 4 and 5 with dirt, then with mud.
Rifle make, model, and caliber: Romanian WASR-10 in 7.62x39mm
Approximate air temperature during testing: 30 degrees F
First clearable malfunction from sand : 1 3/4 tsp
Total failure from sand: 2 1/4 tsp
First clearable malfunction from dirt : 1 tsp
Total failure from dirt: 1 1/2 tsp
First clearable malfunction from mud : N/A
Total failure from mud: N/A
I started out using 1/8 tsp increments of sand, but after six of them without the rifle so much as hiccupping, I decided to switch to 1/4 tsp dollops to save some time and ammo. I left the 1/8 measure in the procedure, though, because I doubt some other rifles would be as resilient as the AK.
The sand and dirt created different malfunctions in the AK. Being dry and small, the sand tended to run down into the magazine. After 1 3/4 tsp of sand, it caused failures in feeding rounds out of the mag, but these I was able to clear with a simple tap-rack-bang procedure. By 2 1/4 tsp, the magazine follower was inoperable -- the follower was stuck and wouldn't apply enough pressure the cartridge for feeding to occur (this was a magazine I knew to be reliable). Had I changed magazines, the AK would have continued to function for a good while longer.
The dirt had a different modus operandi. It was too coarse to percolate down into the mag, so it got shoved into the empty areas of the receiver. I was hoping that it would be pushed back into the spacious rear area of the AK receiver, but this didn't not happen. The first malfunction, after 1 tsp of dirt, was a failure to completely chamber a cartridge. I was able to fix this by simply smacking the bolt handle forward manually. The terminal problem was with comacted dirt building up on the rear face of the barrel, to either lateral side of the chamber. By 1 1/2 tsp, enough had glommed on there to prevent the action from going into battery at all. I had to strip the rifle and scrape the stuff off to get it working again.
I came back from the test pretty impressed with the AK. Two teaspoons of sand or dirt doesn't seem like much, but compared to the volume of the rifle's insides, it's quite a lot. I don't have anything to compare it to, though. When I go back to the range to do the mud portion of the test, I plan to run the whole test on another of my autoloaders.