Would it be technically right to say that the AR15 has no Sear but, rather a Disconnector, that traps the hammer until the trigger is reset and the sound you hear are just the engagment points on the hammer and trigger making contact? Also, would it be technically accurate to say that the M16 has an “Auto Sear” that is only applicable when firing full auto? I find that when most people are asked to identify the Sear on these weapons they will point out the Disconnector and If asked about the Auto Sear on an M16, asking them what it is or does, most will respond with “I don’t know”.
Additionally, when the selector lever is moved from semi to auto it depresses a tail on the disconnector which tips it back and mechanically takes it completely out of the equasion.
Selector lever and disconnector on the select fire versions are shaped different than what is found in the AR15 to accomplish such.
The sear of an AR-15 or M-16, in semi auto, is the nose of the trigger that engages the cock notch in the hammer. The M-16 also has an Auto sear that, when in auto or burst, holds the hammer cocked until the bolt carrier trips the auto sear thereby releasing the hammer.
The FBI put out an excellent animation that allows you to select semi, burst, or auto and watch the internals work. You can zoom in on the trigger group, and clearly see the differences in how they operate depending on which “mode” you select. I couldn’t find it online, but maybe someone with better search-fu could find a link to a download.
I saw it in the Colt Armors Course and it is awesome, but I cannot find it anywhere online. Does anyone have a clue on how to get it? Would love to have it for my soldier, it’s a pain to explain it to people that can’t get it.
Although the program has leaked out, it isn’t readily available. Send me a PM with an email address and I will try and get it to you. I need either a Yahoo or Hotmail address. Gmail won’t allow it.
I really like the animation and photos, thanks. Who manufactured the hammer in the photos? The full auto cock notch on the hammer is interesting. The original Colt style is the only one I am familiar with.
I would be interested to see an animation of how the 3-round burst FCG functions. I have a complete understanding of semi- and full-auto configurations, but I never see any documentation or photos of the burst group. Not that I’d want one myself, but I am curious about the design.
Does that simulation have an option to show a burst group cycling?
It does, but from looking at it, it doesn’t really show exactly how the mechanism only fires three rounds, as opposed to being fully auto (at least from what I can see). I’m no engineer, however, so maybe I’m just missing it.
