Lancer 2320-32 L5AWM AR-15 Magazine 20RD .223 REM/5.56 NATO Translucent Clear - 223 Remington/5.56 NATO Caliber, OEM Origin

Although I really like the design on these magazines, I found that when they were inserted into the magazine well of my rifle, the top cartridge popped halfway out causing the rifle to jam when the bolt was closed. I have found at least one report on the internet of another person who has had the same problem. Upon contacting Lancer, I was told "If you are slapping the bottom of a magazine (especially if downloaded on an open bolt) to confirm that it is seated, it can cause the spring to compress and allow the rounds to unstack. This could result in popping out rounds." OK, but you have to "slap" the bottom of the magazine to get it into the magazine well of the rifle. Furthermore, I had no problem with the Magpul, GI, or Lancer 30rd magazines. A shame, because I really like the design of the Lancer and the 20rd magazines would have been great for the range.