In the past I’ve mentioned that I don’t spend much time on the various gun forums (‘fora’, to be excruciatingly correct.) My free time is too precious to spend wading through such drivel as “my instructor can beat up your instructor” or “the .45 is so powerful it knocks people off their feet!” The only time, in fact, that I look at a forum is when I’m eating breakfast or lunch and have nothing better to read.
It was at lunch last week that I came across one of my personal favorites: the statement that stacking (increase in trigger pressure toward the end of the stroke) is a function of the mainspring used. It’s usually stated in the form “don’t buy a revolver with coil springs – it causes stacking. Buy leaf spring actions to avoid stacking.”
Hogwash, and what’s more it’s easily illustrated to be such.
S&W revolvers, particularly the ‘N’ frames, are known for having pretty linear trigger pulls. They use leaf springs. Colt revolvers such as the Python and Detective Special use leaf springs as well, yet are (in)famous for their stacking triggers.
On the other hand, the GP100 has a relatively linear trigger, similar in travel to an ‘N’ frame Smith. It uses a coil spring. Wait a minute, though – the earlier Ruger “Six” series (Speed-Six, Service-Six, etc.), despite having a very similar action design, stack noticeably.
Simple. The type of spring, coil or leaf, has very little to do with the amount of stacking in a trigger. The real culprit is the geometry of the double action sear. The stacking on a Python, for instance, can be eliminated by changing the geometry of the sear surfaces. The Ruger “Sixes” can likewise be modified to produce a linear pull through the simple expedient of reshaping certain parts of the sear. If stacking were caused by the spring alone, this kind of modification wouldn’t be possible.
Of course this doesn’t address the implicit assertion that stacking is bad and linear is good. Some folks prefer their triggers to stack and seek out those guns that do. The one thing they don’t have to consider is the type of spring!
-=[ Grant ]=-