No True Two Stage Triggers?

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Curlyjim
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Joined: Thu Feb 26, 2015 5:32 pm
Location: Utah

No True Two Stage Triggers?

Post by Curlyjim »

I'm curious why the LP10, 162M, P44, and LP400 don't have true two stage triggers while the IZH 46M does. I've looked at all the manuals on these pistols and the video on the LP400 and they all seem to be a single stage trigger with a simple trigger preload against a spring. Apparently this design works just fine, but I would think that a true two stage trigger would be easier to adjust precisely. I also noticed that all the manuals say to not mess with the sear engagement screw. I'm not surprised because safe sear engagement on a light single stage trigger can be tricky business. Just curious.

Curlyjim
mctrucky
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Location: UK

Re: No True Two Stage Triggers?

Post by mctrucky »

Not sure if one of us is missing something, but here goes.

On the Morini (I assume the others are the same, but don't know) there are two springs, first stage and second stage. The second stage spring comes into play at the point you set it to come in. So both first and second stages are progressive (i.e. get stiffer the harder you pull them as you stretch the spring).

The sear is released immediately on movement of the second stage.

So my first stage is set to say 300 grams, so as I pull progressively against the trigger the second stage does not come into play until I hit 300 grams, the second stage is set at 525 grams (well actually the spring is set at 225 grams, but I still have the 300grams applied from the first spring), and so the trigger does not move any more between 300 and 525 grams of pull. I can progressively increase trigger pressure until I hit 525 grams when the trigger starts to move again and the sear is dropped.

I call this two stage?

McT
pgmlml
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Location: Lisbon

Re: No True Two Stage Triggers?

Post by pgmlml »

I think this graphis can resume everything, and in the end, what counts is the ability to dial the trigger so you can get the "curve" that you want!

My LP400 and my sold Benelli kite had a 1st stage spring that would sum to the second stage spring. This means that the 1st spring will be adding weight to the trigger after the first stage, because of the trigger travel. So if I could measure the weight of the second spring in separate the total wieght would always be more. Another thing I've noticed is, even without springs, the sear adds some weight to the trigger. I Just try to feel it (and measure it) like in the graphics...
There are other limitations, like if I set a small first stage travel, the initial weight will always be higher... I can say the sear adjustment on my LP400 is so small, but I never had accidental discharge (worst case scenario, it doesn't lock)!
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rmca
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Re: No True Two Stage Triggers?

Post by rmca »

Curlyjim wrote:I'm curious why the LP10, 162M, P44, and LP400 don't have true two stage triggers while the IZH 46M does.
The reason is simple... They don't need it.

The whole reason for a double stage trigger is that you have lots of engagement of the sear to the hammer/striker in order for the gun to be safe.
When you press the trigger to take out the first stage, you remove a big chunk of that engagement, leaving just a tiny bit for the second part. This gives you a very precise let off point.

But it also increases the weight of the trigger, and the parts need to be smooth so there's no feel creep.

You just don't need that sort of engagement in a match pistol or rifle, like you do on a military one, so the system is made simpler.

Hope this helps
Tim S
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Re: No True Two Stage Triggers?

Post by Tim S »

rmca wrote:You just don't need that sort of engagement in a match pistol or rifle, like you do on a military one, so the system is made simpler.
And yet all the major manufacturers of 10m and 50m rifles supply a two-stage trigger as standard. Most can be set to single-stage if desired, but a two-stage is standard.
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rmca
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Re: No True Two Stage Triggers?

Post by rmca »

Tim S wrote:
rmca wrote:You just don't need that sort of engagement in a match pistol or rifle, like you do on a military one, so the system is made simpler.
And yet all the major manufacturers of 10m and 50m rifles supply a two-stage trigger as standard. Most can be set to single-stage if desired, but a two-stage is standard.
No... a two stage trigger moves the sear in the first and second stage.
Most match triggers have a first stage take up (no movement of the sear) then a very short second stage that moves the sear a fires the gun.

Hope this helps
mctrucky
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Location: UK

Re: No True Two Stage Triggers?

Post by mctrucky »

So a 'proper' two stage trigger is all about safety - i.e. stage one takes a massive amount of sear overhang away; and stage two releases the last little but - thus meaning if you are not pulling the trigger the sear is a significant mechanical block to the gun firing rather that just hovering on the edge. I can see the point in 'field' guns that are getting knocked about; and perhaps do not have the ultimate quality of manufacture. But for high quality target guns not only is it unrequired, it is also detrimental in feel. It's good to learn stuff :-)

McT
Curlyjim
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Location: Utah

Re: No True Two Stage Triggers?

Post by Curlyjim »

Thanks for the responses everyone. RMCA is probably right, it's not really needed for a strictly target gun. BTW a good video on how a two stage trigger works is here...

https://www.youtube.com/watch?v=sHy2rlTbzis

It's a rifle trigger, but it works similarly in a pistol. Watch the sear movement at the top as the first stage is worked.

I don't agree that a two stage necessarily makes the trigger heavier because the parts still work against springs and have adjustments for weight. The 46M has a true two stage and my experience with that and with a couple of my sporting air rifles is that you can adjust a two stage to get a variety of trigger feels. Some people like a roll trigger, some people like a sharp break with no creep at all. A true two stage makes it pretty easy to get either one. That's why I thought top end guns would have a two stage...so people can easily tweak their triggers exactly how they like them.

It's a little annoying that the manufacturers keep calling their triggers 'two stage' triggers when they're not. I have no problem with calling them match triggers, but two stage they're not. It just adds confusion where it could be avoided.

Curlyjim
spektr
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Re: No True Two Stage Triggers?

Post by spektr »

I don't know exactly what to call myP44 trigger, but I can set the first stage length and weight, as well as the trigger break weight separately.
Over-travel is a third adjustment. I like a long first stage that allows me to find and feel the sear
and almost no movement after that....
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rmca
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Re: No True Two Stage Triggers?

Post by rmca »

Curlyjim wrote:I don't agree that a two stage necessarily makes the trigger heavier because the parts still work against springs and have adjustments for weight.
Don't forget that the total weight of the trigger pull is (usually) the sum of the first and second stage springs plus the friction of the sear to the hammer. The more engagement you have, the more friction you are likely to have, even if the parts here smooth. Again think military weapons vs target weapons.
Curlyjim wrote:It's a little annoying that the manufacturers keep calling their triggers 'two stage' triggers when they're not. I have no problem with calling them match triggers, but two stage they're not. It just adds confusion where it could be avoided.
Agreed.
spektr wrote:I don't know exactly what to call myP44 trigger
Technically it's a single stage trigger with adjustment for the "takeup" weight and length, adjustment for the let off point weight and length (amount of engagement on the sear/hammer), and adjustment for the overtravel stop.
As are most target guns...

Simple hein? ;)

Hope this helps
Gwhite
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Re: No True Two Stage Triggers?

Post by Gwhite »

I don't understand what the problem is. On the Pardini SP and the Benelli MP90S, you can adjust the triggers for either a single stage, or two stage trigger. The way the mechanisms work is different from a classic two stage trigger, but the feel of the critical force vs distance characteristics can be set to be nearly identical.

I have my wife's SP set for a single stage trigger, and my SP is set up to mimic a 2 stage trigger like an old High Standard. After trying each, my daughter requested that I set up my Benelli MP90S for a single stage. No problem.
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