The LS

The ACRD15LS is the ACRD15 with the over-travel problem solved in the part itself. It carries an integrated lever stop, so there's no separate over-travel device to buy, install, or tune — including on Geissele triggers, which previously required one. It ships with shims for the M16 pocket, so the fitment variation you find across M16 lowers is handled in the box. Same core mechanism as the ACRD15: installs into a standard AR-15 lower with no machining, no filing, and no fitting, and every round requires a discrete, mechanical trigger reset.

What the lever stop changes

On the standard ACRD15, over-travel is controlled by whatever the build already has — and on a Geissele trigger that meant adding a separate over-travel device before the system would run correctly. The ACRD15LS integrates that stop into the lever, so travel is limited by the module's own geometry rather than by an add-on part stacked on top of it.

Practically, that means one less component in the rifle, one less thing to source, and one less variable in a build that's already got plenty. The stop is a machined feature, not an adjustment screw — it can't back out, drift, or need re-setting after a few hundred rounds.

M16 pocket shims, included

M16 lowers vary in the fire control pocket — enough that the same module can sit slightly differently from one receiver to the next. The ACRD15LS ships with shims to take that variation out. Fit the module, add shims if the pocket runs loose, and you get the same seated geometry regardless of which lower you're building on.

How the lockout works

When you break a shot, the bolt carrier travels rearward and the underside of a full-auto profile carrier rides over the reset lever. The lever drives the actuator, the actuator forces the trigger forward into a hard reset, and the trigger is then mechanically locked out. It physically cannot move rearward again until the carrier has returned fully into battery and the disconnector hands the hammer back to the sear.

The mechanism is incapable of releasing the hammer while the bolt is out of battery — that's an enforced property of the geometry, not a software setting or a calibration that can drift. One pull, one round, by design.

With sustained rearward pressure, the next shot breaks the moment the bolt locks into battery.

Build

The housing is CNC-machined from 7075-T6 billet aluminum. The lever and actuator are CNC-cut from D2 tool steel and nickel-plated for surface hardness and corrosion resistance — D2 holds an edge under the kind of repeated impact loading these parts see, and the plating keeps that surface intact through thousands of cycles. Everything in the assembly is CNC-produced, so unit-to-unit consistency is a function of the machine, not the operator.

What your build needs

The ACRD15LS is designed around standard mil-spec AR-15 geometry and works with KAK-pattern 90° safety selectors in either two or three positions and with M16 3 position safety selectors. It is not compatible with 45-degree (short-throw) selectors. Geissele triggers run directly — no over-travel device required.

The trigger needs to be mil-spec style. The hammer does not — unlike the standard ACRD15, the LS carries no mil-spec hammer requirement, so aftermarket and speed hammers are fair game. Your existing trigger group stays in the rifle either way.

The one non-negotiable is the bolt carrier group. The ACRD15LS reads its cycle from the underside of a full-auto profile carrier — a semi-auto profile carrier doesn't have the geometry to engage the reset lever and the system will not cycle without it. If your rifle is currently running a semi BCG, plan to swap it.

If your lower or build sits outside a typical mil-spec configuration, send a message before you order. Catching a fitment question up front is faster than fighting one at the bench.