EMR-A is a long in development ambidextrous magazine release for .223 and .308 AR receivers. Original concept and design was complete in 2015. After numerous changes to the mag catch geometry and lever shapes, final design was made into working prototypes in 2017, and first shown in public at Cola Warrior West III.
EMR-A is an ergonomic ambidextrous magazine release. The placement of its lever is well thought out to closely mirror the magazine release button on the right side. The portion immediately below the bolt catch's lower paddle has a lower profile to avoid interference, heretofore a common drawback of popular ambidextrous mag catches, it is also left smooth. The serrated length of the lever is split into a shallow V shaped serrations (80%) that conform to the curvature of the user's finger, and straight serrations (20%) that form a natural index point, and provide additional traction. We refer to the design as Multi-faceted Control Surface, the difference MCS makes has to be felt to be fully appreciated.
Two lever options are available. Standard and Extended Reach (about 0.09" longer than standard). Force amplification achieved from a lever means the extended reach lever is easier to reach, it's also easier to press than the standard lever. For users with small hands or shorter fingers, the extended reach lever makes the EMR-A a joy to use. For duty and defense ARs, we recommend the standard lever.
A 10.9lb rated magazine catch spring is included with each EMR-A. We've long considered the standard magazine catch spring to be rather weak (rated at 8.3lb), accidental / unintended mag drops can take place if a user slings his weapon, and has gear and pouches on the vest. A stiffer mag catch spring mitigates these risks, thus it is an integral part in the EMR-A package.
EMR-A is available as a part of bundled products (please see drop down menus for options). EMR-A's catch is made from CNC machined 4140 steel and black nitride coated, its lever is 7075 aluminum and Type 3 hard coat anodized. The roll pin has a shear strength of 800lbs.
Standard for Nov. 2019
The LP (low profile) mag catch shaft option reduces the mag catch shaft length by a full revolution, or 0.03. The LP option on the EMR-A (not available for extended length lever EMR-A) reduces the installed height of the right hand mag release button, resulting in a right side mag release button that sits below the mag release fence. This is our latest step to mitigate accidental / unintended mag drop risks.
The LP on the EMR-A will not reduce the EMR-C's installed height on an AR15/M16 to the point where EMR-C doesn't constitute accidental / unintended mag drop risks. The LP option's shorter mag catch shaft aims to reduce the installed height of a TDP spec mag release button (such as our EMR), it isn't a solution for extended mag releases, the installed height of which would require a drastically shorter shaft to offset. EMR-C is meant for 7.62mm ARs, even though it works on an AR15 / M16, we suggest it be relegated to 7.62mm ARs and gaming ARs, not for defense and duty.Notes:* EMR-A's lever pivots on the receiver.* EMR-A needs to be removed before installing / removing the trigger. EMR-A is installed and removed in the same manner as a factory mag catch.
* Please wear eye protection while installing EMR, EMR-C, and EMR-A with the 10.9lb mag catch spring, there's considerable spring tension in the 10.9lb spring.
* Geissele's Maritime Bolt Catch. Material from either the top edge of EMR-A's lever, or the bottom edge of Maritime Bolt Catch's lower paddle may need to be removed for both to work together. The close proximity of these two control surfaces makes this combination less than ideal.
* CMC's anti walk pins
* KNS Gen 2 anti-rotation trigger/hammer pins. KNS Gen2 Mod2 and Gen JJ, and Gen ST (Spikes Tactical) are compatible with EMR-A with standard lever, but not with extended lever. Gen2 Mod2's pins connecting bar may require minor fitting on thicker receivers to create adequate clearance for the EMR-A's lever when pressed.
* HK 7.62mm AR style rifles, MR762 series.
* Hodge Defense Mod 2 lower receivers.* Battery assist device levers.
* Receivers with the left side fence around the bolt catch and mag catch, such as some CMT, Magpul and AR15.com billet receivers. EMR-A requires the left side of the receiver to more or less adhere to TDP spcs.
* May not be compatible with Seekins SP223 and AR10 B receivers.* Due to lack of standards for 308 ARs, EMR-A may not work with 80% 308 ARs.