Quoted:


First off I'd like to say Hi! Im new here on the forums and to AR-15's. Im saving to get AR-15 parts and put one together. I have a few questions about the internal operation.   Welcome

The 8 "teeth" on the bolt, are there grooves these fit in?   They lock into the barrel extension before the chamber

And there's also a cam pin near the bolt, where is it and whats it do?  It goes in at about the 10 o'clock position through the carrier into the bolt.  Basically keeps lets the bolt and carrier work together

And just in general, how does the ejector spring get enough space to expand and kick the round out?   Spring contracted when loaded, then expands after being fired to throw out the casing

It seems whatching the Bushmaster animations that the spent case actually hits on part of the mag.  Casing is ejected and bounces off, usually, the deflector.

And  FINALLY,how does the extractor get around the rim of the case?  Because of the ejector spring