The Geissele G2S is a drop-in two-stage trigger for AR-15 and M4 pattern rifles, fitting Mil-Spec lower receivers that use .154 in trigger and hammer pins.
Geissele's gateway two-stage trigger — the G2S delivers the house pull at the sharpest price in the line-up.
The Geissele G2S (05-145) exists to put a genuine Geissele two-stage into more rifles. The pull follows the SSA's profile — smooth first-stage take-up into a crisp, reliable second-stage break — manufactured with streamlined production to reach a price point, not by cutting the metallurgy or the safety margin that make Geissele triggers trustworthy.
For a first trigger upgrade, the G2S is transformative: mushy, gritty factory pulls become a clean two-stage you can actually shoot to the rifle's potential. It drops into any Mil-Spec AR-15 lower and runs full-power ignition springs.
Why shooters choose the G2S
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True Geissele two-stage pull — SSA character, accessible price
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Crisp, repeatable break — an immediate upgrade over any factory trigger
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Full-power ignition springs — dependable primer strikes
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Drop-in Mil-Spec fit — standard .154 in pins
What the G2S fits
The G2S is a drop-in fit for AR-15/M4 pattern lower receivers using Mil-Spec .154 in trigger and hammer pins, so it suits a UK straight-pull AR-15 build as readily as any other AR-pattern lower. It will not fit large-pin receivers — confirm your pin size before ordering. Installation is armourer-level work; carry out full function and safety checks after fitting and before live fire.
Specifications
| Platform |
AR-15 / M4 |
| Fits |
Mil-Spec lower receivers with .154 in trigger and hammer pins |
| Type |
Two-stage trigger |
| Made in |
USA |
| Brand |
Geissele Automatics |
| MPN |
05-145 |
Your first Geissele — and a proper one. Order the G2S today — in stock at Xtreme Tactical Gun Parts with £5 tracked UK delivery in 7–10 business days.
Explore more: all Rifle Triggers, AR-15 Parts & Accessories or browse all Geissele Automatics.
