ABC/R (Augmented Bolt Catch/Release) with its angled and larger top paddle and lower paddle with increased surface area, is purpose designed for use with AR15/M16 receivers equipped with ambidextrous magazine releases. Specifically, it is designed to address the difficulty with accessing the factory bolt catch's lower paddle with an ambidextrous magazine catch, such as Norgon's Ambi-Catch, on the receiver. Many of the ambidextrous mag release's lower paddle is on the same vertical plane as the factory bolt catch lower paddle, making identification difficult by feel, especially with a gloved hand.

The ABC/R's chief effort is focused on that single issue. The lower paddle protrudes further, and is angled at 10 degrees to give it even more surface area. These measures put the lower paddle and Ambi-Catch's paddle on different vertical planes. That done, they worked on the top paddle. While they don't use it ourselves, preferring to pull back on the charging handle instead to load and reload, they do recognize far more users use it, so the ABC/R's top paddle is made larger, and given a 5 degree angle at the lower 50%, and 10 degree angle at the upper 50% cant. The angled paddle makes it easier for the palm or thumb to access.

The notch immediately above the ABC/R’s lower paddle isn’t there by accident. As you run your finger down the bolt catch towards the lower paddle, the notch is meant to provide tactile feedback to indicate the beginning of the lower paddle. It is important be able to differentiate one control surface from another, all without diverting one's gaze to it.

FB (forward biased) is for right hand users that wrap their left hand around the magazine well, and use their left thumb to press the bolt catch's upper paddle.  The FB version has the upper paddle shifted to the muzzle end to facilitate this reloading method. Incompatibilities:

The "butterfly" lower paddle's horizontal extension increases the lower paddle's surface area, but stops short of reaching the bottom of the bolt catch in order to create a stand off distance between the extension and an ambidextrous magazine catch's lever.  It is their opinion and observation that close proximity of two control surfaces is best avoided.  The butterfly lower paddle has increased surface area, and doesn't interfere with an ambi mag catch's lever.

Machined from billet 8620 alloy steel and heat treated with DLC finish. The ABC/R v3 is proudly designed and made in the USA. Weight: 0.4 oz

Please NOTE:

• ABC/R is designed and made for TDP spec AR15/M16 in 5.56mm.  Due to the wildly varying configurations of PCCs it is not advisable to use ABC/R on 9mm carbines. Do not use ABC/R on PCCs.
• ABC/R is machined from a solid piece of 8620, tool marks are sometimes inevitable, they are cosmetics in nature and have no impact on functions.  For anyone that cares more about how things look than how they work, there are lesser built and less expensive bolt catches that have no tool marks.  They are not in the business of making decorations to look at, or color matching.  They design and produce components for defense, LE, and MIL issued weapons.
• ABC/R v3 with forward biased upper paddle may need minor fitting to work with BCM Mk2 upper receivers.