Forward Controls Design ABC/R v4

The Forward Controls Design ABC/R v4, short for Augmented Bolt Catch / Release, solves a problem most bolt catches ignore: on a rifle with an ambidextrous magazine release, the right-side mag lever and an oversized bolt catch sit close together and get confused under stress or gloves. FCD shapes the ABC/R specifically around that conflict. The lower paddle is extended and angled ten degrees to create physical separation from the ambi mag-catch lever, and a tactile notch above it lets a gloved hand identify the control by feel.

It is the most heavily engineered catch here. The body is machined from billet 8620 alloy steel, heat treated, and finished in DLC for hardness and corrosion resistance. The upper lock-back paddle is offered in forward-biased, non-offset, and rearward-biased geometries so the shooter can match it to their lock-back technique, and the "butterfly" lower paddle increases surface area while keeping a safe standoff from the mag release. It includes the roll pin, plunger, and spring. This is the 5.56 part; FCD makes a separate large-frame version.

Choose the ABC/R v4 when you are building a serious ambidextrous AR-15 and want the controls deconflicted rather than just enlarged. It is overkill on a basic rifle with a single-side mag release, where the Geissele or Seekins gives most of the benefit for less money, but it is the right answer for a duty or competition lower running an ambi mag catch.