The Geissele Super Dynamic Enhanced (SD-E) is a flat-bow two-stage trigger for AR-15 and M4 pattern rifles, fitting Mil-Spec lower receivers that use .154 in trigger and hammer pins.
The Geissele Super Dynamic Enhanced (SD-E, 05-167) marries the SSA-E's crisp, light second stage with the flat trigger bow of the Super Dynamic line. The flat shoe's geometry adds leverage and puts your finger in the same place every shot; the enhanced internals reward that consistency with a break often compared to snapping glass. Together they make the SD-E a strong pick for precision AR-15 builds whose owners still want two-stage safety margin.
Geissele's machining and finishing keep the pull consistent across thousands of rounds, and full-power springs preserve dependable ignition. Non-adjustable — there is nothing to set up.
Key Features
- Enhanced light second stage — a very crisp, clean break
- Flat trigger bow — repeatable finger position, added leverage
- Two-stage precision with safety margin — prep, then commit
- Full-power ignition springs — dependable primer strikes
Compatibility & Fitment
Drop-in fit for AR-15/M4 pattern lower receivers with Mil-Spec .154 in trigger and hammer pins. Large-pin receivers are not compatible — confirm your pin size before ordering. Installation is armorer-level work, with function checks to follow before live fire.
Technical Specifications
Platform | AR-15 / M4 |
Fits | Mil-Spec lower receivers with .154 in trigger and hammer pins |
Type | Two-stage trigger, flat bow |
Made in | USA |
Brand | Geissele Automatics |
US Shipping & Support
Shipped from D&R Sports Center in the USA with fast, tracked delivery. Questions on fit, mounting or which model suits your setup? Our team is glad to help before and after your purchase.
Frequently Asked Questions
Will the SD-E drop into my AR-15 lower?
It is designed as a drop-in for AR-15/M4 pattern lowers with mil-spec trigger pins. Large-pin receivers and some non-standard lowers will not take it, so check your pin size before ordering. If in doubt, measure the pin holes or ask us with your receiver details.
What is the SD-E aimed at?
The SD-E is the Super Dynamic Enhanced: a two-stage trigger on a flat bow, set up as the lighter, more precision-oriented member of the Super Dynamic family. The flat shoe puts your finger lower on the bow, which changes the leverage and makes the break feel more consistent to many shooters. It suits marksmanship and general precision work more than close-range speed shooting.
How does it compare with the SD-C?
Both are flat-bow two-stage triggers, but the SD-C is set up as the combat-weight option with a heavier, more service-oriented pull, while the SD-E is the enhanced, lighter-feeling one for precision. If the rifle is a working carbine, the SD-C is the safer choice; if it is a target or DMR-style build, the SD-E is the natural pick.
Do I need any other parts to fit it?
No, it assembles into the lower with standard trigger and hammer pins in the usual positions, so no extra hardware is required if your existing pins are in good condition. Anti-walk pins are optional rather than necessary.
