I don't know if anyone else here knows it, but DoD uses Bushmaster 20" rifles and 14.5" carbines in their Squad Simulators. These, of course, are recoil-only, powered by compressed air.
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The OP asked me to post these pictures, it's my Armalite, made in June of 2005. Yes I should have cleaned her up before pictures but I'm in the middle of seeing how far she will go until she cough's, so all it got was a quick wipe down. Oh the bottom picture is a CMT on my 6.8, not impressed with its dimples on the key.
http://i162.photobucket.com/albums/t...7/P9150062.jpg
http://i162.photobucket.com/albums/t...7/P9150063.jpg
http://i162.photobucket.com/albums/t...7/P9150064.jpg
Here are some things that I found during my class that wern't marked on the chart and thought should be.
Pictures from ArmaLite...
http://www.hunt101.com/img/517435.JPG
http://www.hunt101.com/img/517436.JPG
http://www.hunt101.com/img/517437.JPG
http://www.hunt101.com/img/517438.JPG
http://www.hunt101.com/img/517439.JPG
http://www.hunt101.com/img/517440.JPG
http://www.hunt101.com/img/517441.JPG
This is all I have for now... I need to go in and try to manualy resize some of these to upload.
Pat :)
From the looks of the staking of the gas key in the pictures there is no metal moved into the screws and makes it only cosmetic.
So it appears from your photos that Armalite:
(1) doesn't do a good job of staking the key
(2) tracks bolts by lot numbers (TOS reports that Armalite performms HPT against samples within lots, but not against every bolt)
(3) machines M4 ramps pre-anodizing
(4) stakes the receiver extensions
(5) parkerizes underneath the FSB
(6) includes an o-ring with their extractor (but I can't tell if the sping used is a HD model or not, and if teh insert is blue or black)