Trigger pull alterations - some thoughts...

In the spirit of two earlier articles I posted on sport shooting and accessory/part selection, I wanted to share some lessons I've learned the hard way (not the "Oh crap, I'm going to die" hard way, just the "Hey, something's not right and I spent money on this" hard way). 

I own a CZ-85B that I had customized specifically for sport shooting.  As part of the custom work, I had a trigger job done that resulted in an amazing improvement in the crispness of the trigger and the pull weight reduction.  When I went to test fire it in the middle of the ammo shortage, I had a mix of PRVI and PMC ammo to run through it.  The PMC ran reliably throughout, but I experienced several failures to fire with the PRVI.  I took the ejected rounds and ran them through my other 9mm I had brought (unmodified), and they fired.  I was a little confused at first, because my CZ had always run whatever ammo I fed it previously.  Then I decided to read the description of the work that had been done to it.  Included in the trigger job was a lighter mainspring.  One of the things your mainspring influences (other than trigger weight) is how hard the hammer strikes the firing pin.  A lighter mainspring means a lighter hammer strike.  Ammo with harder primers (PRVI, TulAmmo, etc) may not reliably fire in a gun with a lighter mainspring. 

Does this concern me?  As it relates to my CZ, no.  As I stated, I wanted this gun modified specifically for sport shooting.  When I sport shoot, I control the ammunition that I feed it.  I'm not quite to reloading yet, but I can try multiple types of ammo, and feed it the one it likes best.  For those of you who are planning for the Day of the Zombie Horde or other self-defense/societal breakdown scenario, this should concern you.  Unless you have cases of ammo stacked in your garage (and judging from the shelves at Wal-Mart, some of you do), there will come a point when you will need to scavenge for ammo.  When that happens, you need a gun that will reliably fire whatever you can find.  Gun designers are relatively smart people, and they design guns to perform in a variety of scenarios.  If you choose to tune your gun for a specific purpose, that is perfectly fine, but be aware of the unintended consequences that may come of it.

My second lesson learned was with modifications made to my Glock.  I installed a spring kit and reduced weight trigger connector.  I liked the trigger pull so much when sport shooting that I considered changing out the springs on my carry pistol as well.  Then two things happened: 1) I actually read the spring manufacturer's instructions and 2) I paid more attention during my dry-fire practice.  The manufacturer's instructions specifically state that the reduced power striker spring, while excellent at reducing trigger pull weight is NOT to be used in a defensive pistol.  Why?  See above for my experience with the CZ.  Second, during dry-fire, I glanced down as I worked the slide to reset the trigger and noticed that the trigger was not resetting fully forward.  It was resetting far enough to be ready to fire, but not far enough to reset the trigger safety mechanism (that annoying lever on the trigger everyone loves to hate).  Per GLOCK’s website, “The trigger safety is a lever incorporated into the trigger. When the trigger safety is in the forward position it blocks the trigger from moving rearward. The trigger safety and the trigger must be fully depressed at the same time to fire the pistol. If the trigger safety is not depressed, the trigger will not move rearward and allow the pistol to fire. The trigger safety is designed to protect against firing if the pistol is dropped or the trigger is subjected to lateral pressure.”  In other words, if it doesn't reset properly, and my shirt/jacket gets in the trigger guard or I drop the pistol, bad things could happen.  The lower weight trigger spring I installed is the most likely culprit.  Since I plan to go to the range this weekend, I will re-install the original springs this week and dry-fire to see if the problem improves.  If I find the lighter springs are causing the problem, I will permanently remove them.

In summary, it's your gun, tune it the way you want, but ensure that you have done your research and understand any unintended consequences that may occur.  Just because it’s the latest and greatest, or the manufacturer promises that this is the last upgrade you’ll ever need, or your buddy tells you how much faster he is with his super-light trigger pull doesn’t necessarily make that set-up right for your intended use.