Description
This is the Geissele SSA built for Colt large pin lowers. Colt AR-15s made from about 1990 to 2009 use .169 in trigger and hammer pins instead of the standard .154 in, and normal aftermarket triggers will not fit them. The fire control is otherwise the same SSA: two-stage, non-adjustable, 4.25 to 4.75 lb total per Geissele, with a 2.75 to 3 lb first stage and a 1.5 to 1.75 lb second stage.
It comes with the M4 curved bow, tool steel trigger and hammer, and a full-power hammer spring. Geissele describes it as a semi-auto only version of the Super Select-Fire trigger, light enough for precise shots but forgiving enough for fast close work. Install is the standard two-pin job, using the large pins that ship with the trigger.
Heads up: Measure your pin holes before you order. If your lower takes standard .154 in pins, you want the regular SSA (05-101), not this one.
Specs
- Part number: 05-123
- Type: Two-stage, non-adjustable
- Pull weight: 4.25 to 4.75 lb total (2.75 to 3 lb first stage, 1.5 to 1.75 lb second stage, per Geissele)
- Trigger bow: M4 curved
- Pin size: Colt large pin, .169 in (1990 to 2009 Colt lowers)
- Fits: Large pin Colt AR-15 lowers
- Material: Tool steel
- Made in: USA
Who it’s for
Owners of a large pin Colt lower who want a real two-stage trigger without swapping receivers. Good for a Tactical Games or general purpose carbine built on an older Colt.
Who should skip it
Anyone with a standard .154 in pin lower, which is nearly every non-Colt AR-15 and all newer Colts. The regular SSA (05-101) is the same trigger for less money. Geissele also makes the S3G in large pin if you want a competition pull in a Colt lower.




