Adjustable triggers are both a blessing and a curse. They are a blessing if you are patient and know how to adjust them properly. They are a curse if you are impatient and prone to knob dickering. (It’s a real word. Look it up.) This is a very unique phrase that I learned while on the set of American Airgunner. Be sure to catch the 2014 season to see if that part made the cut. Anyway, knob dickering is when you play with knobs, screws, and buttons without really understanding the consequences of such actions. This can lead to some real issues, especially when it comes to adjusting sensitive trigger settings.Here’s my personal Hatsan AT44 .25 cal getting ready for a trigger adjustment.
Knowing what does what?
It’s very important to know what screw, pin, rod, or spring does what in a trigger. My first journey down the rabbit hole of adjustable triggers was with a popular drop-in replacement for the stock Crosman/Gamo trigger blade. There were 2 settings. The usable adjustment range was very small and every 16th of a turn made a noticeable difference. It was completely possible, ask me how I know, to go beyond the usable adjustment on either screw and find yourself just chasing your tail trying to get back to “normal.” What’s worse, adjusting too far meant that the gun was very unsafe and could accidentally discharge very easily. Despite all the warnings to the dangers of trying to mess with those settings I did it anyway and about near put a hole in my ceiling. That was many, many years ago and I’ve grown to be a lot more studious, patient, and happy with reasonable results, not needing to push things to the bleeding edge.
Back to the AT44 / BT65 Quattro
The factory pull on an “out of the box” AT44 / BT65 Quattro Trigger, is about 3 to 4 pounds. Now I know that I can get that trigger easily down under 2 pounds, and maybe even a little more with a little time and patience, so let’s get started.Hatsan factory pull weight AT44 Quattro Trigger
First thing will be to remove the magazine, make sure the breach is clear, and then remove the air cylinder. Next, remove the metal trigger guard. With the metal guard removed you’ll have easy access to all three adjustments. As with all the other Quattro trigger systems, each screw has a unique purpose. The rearmost screw adjusts the overall pull tension. This is all you’ll need to adjust most of the time. Turning the screw counter clockwise will decrease the pressure. It’s best to turn it 1/4 turn at a time and then test the results of the change by simply dry firing the rifle. Again, make sure that your airgun has been cleared and that you’ve removed the air cylinder. As you lighten the tension on that screw, you’ll reach a point where the trigger will no longer engage when you cock it. At that point, the trigger is over adjusted and will not function. Simply add a 1/4 turn, 1/2 turn would be better, of tension back onto the spring and you will be at the lightest pull weight.Quattro Trigger at the bleeding edge of adjustment. This has been over adjusted and is not stable. It needs that 1/2 turn back to a reasonable, safe pull weight.
Do you need to adjust the other two screws?
Here’s where things can get a bit tricky. The other two screws play a balancing game that can get out of control very quickly. The front screw adjusts the position of the 1st stage and the middle screw adjusts the position of the 2nd stage. The range of adjustment on these screws is very small. If you get one out of spec, you’ll have a fun time trying to get things back to normal. You can also cause the gun to not cock reliably in the same way it does when you back off the tension too far. Before you start making any changes, make a note of the factory settings. A simple photograph of the stock settings will be a real blessing if you find you’ve reached a point of over adjustment. This way you can hopefully bring things back to a known starting point before trying again. It’s also a good idea to document your changes each time, especially critical if you are new to the process.Hatsan AT44 Trigger Adjustments
When adjusting the front two screws, you need to do one at a time and use 1/16th turn adjustments. As I mentioned above, the usable adjustment range is very, very, small. Most of the time you will be turning the screws counter clockwise, but this is a balancing act, like I said, so you’ll have to really take your time with both of those adjustments and learn how the trigger reacts to each tiny change.
What’s optimal will be different for every shooter. I prefer a light pull of under 2 pounds. I like to feel a distinct 1st stage with a crisp 2nd stage. I think that’s what most shooters are really after. You can get that with the Quattro triggers, but it can take some work and a lot of patience. Take your time and don’t be afraid to put everything back to factory and start over. That will be your best bet to recover from an over adjustment error. Most importantly, don’t do any testing of the trigger with an active airgun. Make sure that you are operating on a completely safe airgun. Only test fire your adjustments with a live airgun in a safe environment, i.e. outside following proper gun etiquette and muzzle control. The moment you take things for granted is the moment you could have a potentially very scary accidental misfire. Ask me how I know….After some work, I found a happy, safe adjustment for my AT44s Quattro Trigger.
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