Measuring trigger pull on a diagonal trigger without a notch

[UnGe]

How to properly measure trigger pull on Izh 46m with Air Venturi trigger (as an example, but there are a bunch of similar ones), and how it is really done during competitions?

Screenshot 2021-10-22 074646.jpg (34.92 KiB) Viewed 1760 times

"The weight of the trigger pull must be measured, with the test weight suspended near the middle of the trigger (see illustrations) and the barrel held vertically."

Picture shows only very symmetrical triggers, where the lowest part is also the middle (or close). But I practically never seen triggers like these :)
What if trigger is asymmetrical, and is placed diagonally to the barrel direction?

AirVenturi-IZH46M-Adjustable-Trigger-Assembly_AV-IZH46MTA_zm6 (1).jpg (50.6 KiB) Viewed 1760 times

- Where is the "middle" of this trigger?
- How to suspend the weight? With barrel vertical it will roll to the very end of the trigger (or even off it)

[David M]

Difficult, one option is to tilt the barrel back until the weight knife edge will sit on the middle of hte trigger finger pad.
Not really a good option but may get you through a local competition with some argument.
The better option is to get a round 160 mm needle file (rat tail) and file a semi circular groove across the trigger pad.
Locate it in the middle of the finger pad. Go just deep enough that the weight will sit with the batter upright.
It gives you a reference point, takes away all argument and keeps equiptment control happy.

[rmca]

- Where is the "middle" of this trigger?

The middle of the trigger is here:

1.JPG (25.8 KiB) Viewed 1672 times

- How to suspend the weight? With barrel vertical it will roll to the very end of the trigger (or even off it)

Two options:
1- A rubber knife edge on the trigger weight, so it wont slide off. Heat shrink tube works great for this.
2- What David said, get a file and cut a small groove. This will be the best bet in the long run, as not every equipment check will be able to weight your trigger correctly, if the standard weight slides off.

Hope this helps

[Gwhite]

One problem with the trigger pull gauges available in the US is that they all still use a roller. I forget when the ISSF changed to a wedge, but it was on the order of 20 years ago.

I've thought about replacing the rollers on my weight set, but I need to make sure the new wedge weighs pretty much the same as the roller, which is quite light. On a force gauge (like the Lyman digital gauge), it doesn't matter, because the weight of the rod & wedge/roller gets zeroed out.

[Spencer]

Difficult, one option is to tilt the barrel back until the weight knife edge will sit on the middle of the trigger finger pad.
Not really a good option but may get you through a local competition with some argument...

8.4.2 The weight of the trigger pull must be measured with the test weight suspended
near the middle of the trigger (see illustrations) and the barrel held vertically. The
weight must be placed on a horizontal surface and lifted clear of the surface.

[Gwhite]

Easier said than done with some heavily angled triggers. That why the notch is a big improvement (on the pistols that have it). If the face of the trigger is at a 45 degree angle in the middle, you still run the risk of having the wedge pop out of the notch.

If the trigger is angled that much, it's usually because the trigger finger is pulling upward at an angle (like IZH in the first post). Despite what the rule book says, having the weight pull in the same direction the shooter does is certainly in the spirit of the rule. I suspect a lot of equipment check staff don't worry about the barrel being perfectly vertical if the trigger pull is at a steep angle, especially if tilting it a bit is the only way to keep the wedge in place.

[rmca]

Here is my two cents on the subject of (angled) triggers:

If they can't be measured CONSISTENTLY as per ISSF rules, then the pistol will fail EQ and you will be disqualified.
The same happens when you set your trigger too close to the weight limit. If it can't lift the weight clear of the table, you will be disqualified.

So you shouldn't set it up to your personal preference, if that means it can't be measured. Find a compromise between the two.
Remember, equipment control trumps personal preference.

If you have a non adjustable trigger, and it can't be measured reliably, file a notch on it or don't compete with that pistol.

Hpoe this helps

Edit: grammer...