Newer models have a “flattop” upper receiver with a Picatinny rail, to which the user can attach either a conventional sighting system or numerous optical devices such as night vision scopes.
The M16 utilizes direct impingement gas operation; energy from high-pressure gas tapped from a non-adjustable port built into the front sight assembly actuates the moving parts in the weapon. Combustion gases travel via a gas tube above the barrel directly into a chamber in the bolt carrier behind the bolt itself, pushing the carrier away from the bolt. This reduces the number of moving parts by eliminating the need for a separate piston and cylinder and it provides better performance in rapid fire by keeping reciprocating masses on the same axis as the bore.[citation needed]
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Colorado: CU regents to vote on gun ban Friday
The University of Colorado regents will vote Friday morning on whether the school should continue its legal battle to keep guns off its campuses. A public comment period for the issue will begin at 10 a.m., prior to the board’s vote. The board meeting will be held on the East Campus and Research Park, in the first floor main conference room of 4001 Discovery Drive, Boulder.
fiber optic sights
http://www.mannyusa.com/Firearms_Training/category/Eotech_sights.html; AR-15 Sights … Aimpoint Comp; ar15 sights; Holsters for Concealment; Sights for AR-15; Ruger 10/22 magazine
Canada: Gun owners hoping for registry changes
The private member’s Bill C 391 before the House of Commons could take hunting rifles off the federal gun registry, something local gun users say they would welcome.