The upper AR is a LMT Defender 2000 M4 16" barrel and the lower one is a Colt 6721 A3 Tactical carbine with 16" midlength gas sytem barrel
My LMT carbine is not a build because LMT doesn't sell individual components back in '05 I bought it separately upper half and lower half because at that time they were not selling complete carbines yet.
The Colt 6721 I also bought in two halves because they were hard to find when I bought it, I removed the factory HBAR heavy barrel sold it and got a Rock Creek - Global Tactical medium contour, midlength gas system 16" mil-spec CMV machine gun barrel steel, 1/7 twist, chrome lined, 5.56 NATO chamber, and M4 carbine feed ramps.
Top LMT M4 carbine:
LMT 16" M4 barrel upper half with A2 flash suppressor
LMT M16 full auto BCG
LMT Tactical latch CH
BCM bolt extractor upgrade kit
LMT Defender 2000 lower half
Knight's Armament (KAC) M4 RAS rails
KAC rail QD sling mount
Magpul XTM FDE rail panels
Norgon ambi mag catch
KNS anti-rotation hammer & trigger pins
LMT ambi selector
Magpul aluminum trigger guard
Magpul MIAD FDE grip
Vltor Modstock FDE
LMT H carbine buffer
Troy rear Battlesight BUIS
Aimpoint Comp M2
LaRue LT-129 cantilever QD mount
Surefire M951C weaponlight
Gear Sector GS-2P two point modular sling
Bottom Colt 6721 midlength carbine:
Rock Creek Barrels - GTS Operator medium contour, midlength, 1/7, 16" barrel
Saylor's Machine Phoenix flash suppressor
LaRue 9.0 free float rails
Magpul XTM FDE rail panels
TangoDown VFG (currently replaced by LaRue FUG VFG)
Colt 6721 upper receiver
Colt M16 full auto BCG
Crane mil-spec extractor spring O-ring
Colt 6721 lower
Norgon ambi mag catch
KNS hammer & trigger pins gen 2
LMT ambi selector
Magpul BAD lever
Magpul folding enhanced trigger guard (no longer in production)
Magpul MIAD FDE grip
Vltor EMOD FDE stock kit
H carbine buffer
Troy FDE rear BUIS
EOTech 551 (no longer in production replaced by XPS series)
LaRue LT-110 EOTech QD mount
Surefire M961C weaponlight
Blue Force Gear Vickers VCAS padded coyote two point sling
Daniel Defense rail QD mount & heavy duty QD sling swivels