While doing the magazine swap today on the 5.56 Patrol, I ran into an interesting issue that others may run across later on. It seems the snap caps are not always to spec and will not properly extract and eject. Since I had not had a chance to fire this rifle yet, I thought I might have a problem so started looking. After looking at how the new mag went in compared to the original and looking at the extractor for fit and function, I decided to try some actual live rounds (which I don't like to do when just doing a function check) and they cycled just fine. The snap cap/proving rounds I was using was a Magpul proving round and A-Zoom snap caps. This is the first time I've had a problem with A-Zoom, so I thought I would pass the info along.