Why the Generation-II GTX 2-Stage Replacement Trigger is Better Than All Its Predecessors. The story of a screw

Post by Steve_in_NC.

For more than a decade, one of the most popular trigger designs – adopted by such easily-recognized airgun marques as Benjamin, BSA, Crosman, Gamo, Remington, Stoeger, Tech Force, Theoben, and Xisico – has been the so-called “Gamo-style Adjustable Two-Stage” trigger.

The enthusiasm for this trigger among manufacturers is easy to understand. The design is mature, proven, reliable, robust, safe, and incorporates resettable safety and automatic anti-beartrap features. Unfortunately, the lack of enthusiasm for it among shooters is also easy to understand. In use, this trigger is heavy, rough, and creepy with an unpredictable break, and the “two-stage” feature is only simulated. In short, it’s a trigger that works reliably and well, but can pose a real obstacle to fun and accurate shooting.

This unique combination of popularity with less than ideal performance is the reason that, in 2004, I undertook the design and manufacture of the GTX replacement trigger. In the intervening years, thousands of GTXs and GTX copies (not all of them authorized) have been sold, installed, and helped to make good airguns better – some say much better. But there was still room for improvement. So in 2009 I took a hard look at the original GTX concept and design from the vantage of a half-decade of experience with trigger re-engineering. The GTX generation II is the result.

From day one (over a half-decade ago), the GTX's (including the unauthorized knock-offs) biggest shortcoming as a first-class sporter trigger, has been a 2nd stage that's too easy to pull through. 

All 2-stage triggers, by their very nature, must always have a 2nd stage with a heavier pull than the 1st stage. This difference in stage weights isn't super fussy, but it does have to be large enough for the shooter's finger to reliably detect it. Otherwise the shooter may inadvertently pull through the second stage - release the shot before he's ready - and miss. 

An ideal ratio of 2nd to 1st stage weights is at least 1.5:1.

Unfortunately, the GTX (and all knock-offs) have never achieved ratios anywhere near that large. An anemic 1.2:1 was always typical. And since designing and beginning production in 2004, I've never quite known why - until I got involved with the development of the GTX Generation-II trigger. As part of reviewing my design files leading up to its production for the reintroduction, I did some long overdue experimentation and found out that the problem all along had been the inadequacies of a rough and asymmetrical screw tip. 

Unlike all other Gamo replacement triggers, the new GTX uses an adjustment screw with a precision polished bearing tip (picture on the right), instead of an ordinary fastener-type machine screw (left).


After six years, the problem is finally fixed. The result is typical measured weight of: 


1st Stage = 14 oz. 

2nd Stage = 1 lb, 5 oz.

2nd:1st Ratio = 1.5:1. 



Nobody who shoots with the new GTX will be likely to miss the difference in feel - nor as likely to miss his target. 

The Generation II GTX Trigger is available from Archer Airguns.