Disappearing first stage (Steyr LP2)

[gimgim]

Hi,
trying to adjust the mechanical trigger I must have messed up something and the following happens:
- The pistol is set (on the bench, by dry firing) with the first and a second stage (at 515g).
- After shooting a few times (no dry fire), the trigger behaves erratically and the first stage disappears (!?!?!).
- If I keep shooting, every once in a while, the trigger will go back (for a couple of shots) to the original setting (two stages).

Any suggestions how to troubleshoot this?
Is there a procedure to bring the trigger to a "default" setting?
The adjustments are not independent, so I wonder if there is a sequence I should follow to avoid going back and forth between the screws.
Thanks

[Ramon OP]

I contacted Steyr about the trigger reset to default settings and did not get a positive answer.

From the Evo manual (5.2)

Too fine adjustment of the trigger stop may
cause inconsistent trigger weight and
release

[gimgim]

Thanks Ramon.

I was able to "solve" the problem yesterday evening by looking at the drawing attached.
(this is the trigger of a used LP2 of which I don't know the history, so I am making a lot of assumptions here)

STTRIG.jpg (19.35 KiB) Viewed 2617 times

First I fully unscrewed (I), (II), and (III). This should get the longest first stage with the minimum weight possible.
Verified than the pistol was still firing like if it didn't have a first stage, and without the tip of the screw (III) touching anything.
At that point, the only possibility seemed to be the sear not being engaged well enough and the pistol firing not because the tip of (III) pushes the lever, but because the hold at the opposite side of it is lifted.

I unscrewed (V), the screw Steyr says shouldn't be adjusted, ever :-) by a tiny fraction (red paint seal was still there, but it wasn't securing the screw) and then adjusted second stage weight (IV), and the first stage length and weight.

Everything seems to be working now. The first stage seems heavy though (compared to the Evo10 I have), so I suspect that the spring for the first stage has been replaced with a heavier one or (is that even possible?) that springs for first and second stage have been swapped (by mistake after taking the pistol apart?)

[David M]

Total reset....
Turn scew 1 anticlockwise to allow trigger after travel.
turn screw 3 to allow 3-5mm travel at the centre of trigger blade.
turn screw 2 to give approx. 300g of first stage weight.
turn screw 4 to give approx. 200g second stage weight.
These are the rough settings.
Now to adjust the sear. (the don't touch screw)
you need 1/8 to 1/2 screw engagement of the sear. The amount of engagement also acts like a second stage travel.
1/8 of a turn will be a break like glass setting and a 1/2 turn a slight roll off.
The lighter you set the second stage weight (screw 4) the more sear engagement you need for reliable operation.
With the pistol cocked slowly turn 5 in until the pistol fires (sear releases) this is the break point. Note the screw head slot angle.
Now back off screw 5 a 1/4 to 1/3 of a turn, re-cock and try the trigger feel. Feel for the second stage travel.
Adjust a very small amount as required but not less than 1/8 trun from break point. (Sear set)
Slowly wind in the trigger stop (screw 1) until the pistol won't fire, then back off 1/2 turn. (Over travel set)
Adjust overall trigger travel to your liking.(screw 3). (trigger travel set)
Now fine tune the second stage weight for your feel but not less than 100g. (150- 200g is good).
Adjust the first stage weight to lift +500g.
If feel and weight is right ,lock screw 5 with nail polish or a small dab of super glue.

[gimgim]

David M: Thank you so much, this is incredibly useful!

[David M]

Easy way to set trigger weight stages.
Correx tension gauge 500g model.

c500r1a1a.jpeg (24.41 KiB) Viewed 2557 times

[gimgim]

It does look fancier than mine :-)
Ordering one, thanks!

[Ramon OP]

Easy way to set trigger weight stages.
Correx tension gauge 500g

David, how do you make sure you are pressing always in the same and "right" direction to get consistent readings?

Great instructions for the trigger reset, thanks !

[David M]

The Tension gauge is used to set the first and second weights.
Pressing the tang on the centre of the trigger you can feel each stage and read the weight increase of each directly on the dial.
Final weight testing is by ISSF Trigger weight.
It is also useful for Free pistol trigger setting.

[Gwhite]

For free pistol, a lever tension gauge is about your only option, but for best accuracy, you need one that reads lighter than for an air pistol. For air pistol & semi-autos, I highly recommend the Lyman digital trigger gauge. They are a LOT less expensive than the lever tension gauges. I know of used one recently in a legal case, where it was checked frequently against a couple calibrated weights. It was never off by more than 0.1 ounces (1 count), and most of the time it was spot on.

https://www.amazon.com/Lyman-7832248-El ... B00162QGLS

The only downside is they have a roller on the pull bar, but you can take that off to get it to better fit in the trigger groove on most ISSF pistols. Unlike fixed weight, the change from removing the roller is zeroed out.

[Ramon OP]

The Tension gauge is used to set the first and second weights.
Pressing the tang on the centre of the trigger you can feel each stage and read the weight increase of each directly on the dial.
Final weight testing is by ISSF Trigger weight.
It is also useful for Free pistol trigger setting.

Thanks David. I know what it is for and how it works. My question is about how to consistently take good measures. If the device is not perfectly perpendicular to the trigger weight anf you don't push it in a straight line perpendicular to the pistol you will not get a precise reading, would you?

When I tried one with my free pistol's ultra light trigger I couldn't reproduce the same movement every time amd the readings where too different.