LP 10 and Morini 162 ei trigger queries

[John Harvey]

I’m just slightly confused in regards to setting up my first and second stage trigger weight on both the LP 10 and Morini 162ei. I’ve been reading the posts from April 7th regarding trigger stage weights and note that: ”apply pressure until the trigger stops moving – this is the first stage”. I’ve only just realized that. My question is – what about the first stage travel adjustment? I thought that this initial trigger movement was first stage travel only (and no real weight involved) – but have I interpreted correctly in now assuming that this is also first stage weight? I’m pretty ignorant in this area.
I’d also like to clear up something which is confusing me reading my LP 10 manual. (which has a print date in it of 03/2005)
In the parts list – item 55.4 is called: first stage pressure adjusting screw.
Item 56.2 is also called the very same. Which one is it? Which one is labeled wrongly – and what is the correct name/use for it? (the one that is NOT the first stage screw)
Final observation. When checking my trigger weight in the dry fire mode – I note that the trigger sear (Item57) hits the grip locking rod (item 27) each time the trigger is pulled.(I obviously have the wooden grip removed to see this). It hits it quite hard – I’d expect enough to have some sort of “recoil/jarring/vibration effect”?? It is quite a small “jar” in the hand when the grip is removed – but I cannot “feel” it when the grip is in place. It certainly has made small marks on the “grip locking rod” where it has touched it each time. I’ve tried moving this rod into different positions to see if there is any position that the trigger sear does not hit on pulling the trigger – but no luck. So – is this normal? Do all of you who use LP 10’s have exactly the same to report? I’d appreciate feedback.

[BJ]

I note that the trigger sear (Item57) hits the grip locking rod (item 27) each time the trigger is pulled.(I obviously have the wooden grip removed to see this).

Does it hit when the rod is held slightly rearwards as it is when installed in the grip?
If it does, theres something wrong.
If it doesnt, its quite normal. The rod is fixed in the grip angling rearwards.

[John Harvey]

Thanks BJ you are right. Carefully placing the grip locking rod in the right position and it appears not to get any contact. To confirm this, I re-fitted the grip and left the tool in the grip screw and then dry fired with my hand on the tool to see if there was an "vibration" There was not. The contact is only made when I dry fire with the grip taken off - meaning the grip locking rod is hanging (swinging) in an abnormal position. This all came about when I was checking the trigger weight with the grip off.
Thanks for the idea.
I'm still at lost about tiem: 55.4 and 56.2.

[BJ]

I'm still at lost about tiem: 55.4 and 56.2.

I cant understand why you are using the parts list to work out how to adjust the trigger when the Trigger adjustment is explained fully with diagrams in a preceding section.

It looks like item 56.2 is mislabeled, I think it should read "Second stage pressure adjusting screw".

[John Harvey]

No BJ I wasn't using the parts list to work on trigger weight adjustment. I spotted the "double" description when I was looking at the part names to post about the trigger sear and grip locking rod contact. I was reading the parts list and looking at the detailed diagram, trying to get some sort of understanding of the pistol parts - I'm far from "mechanical". But after reading the part numbers as above and things like: 72.4 - trigger adjusting spring (sure can't work that one out) and : 75.4 - trigger blade (I can't even find a number that high on my diagram!) - I think I'll stick to just enjoying the "complete item"!

[Mark Briggs]

John,

Firstly, if you're truly writing from Bali, then I can only grin in envy of your location, especially during the six months or so of snowy weather that we get here... LoL

As for trigger adjustment, I'll try to do a "101" level description for you.

Firstly, a two stage trigger is designed such that some or even most of the weight (or pressure) is applied on the first stage. The second stage then appears to the user to be just a small increment over the weight being held on the first stage.

In a usual 2-stage setup for air pistol, your finger will first begin to move the trigger rearwards and compress the 1st stage spring. The distance your finger travels while moving through the 1st stage is the 1st stage travel (sometimes called 'takeup'). Correspondingly, the amount of spring compression achieved while the trigger moves through this first stage provides the first stage weight. On the Steyr the weight is adjusted by turning the adjustment screw inwards, thereby compressing the spring a bit more, resulting in more felt weight as you move the trigger. Some folks like a short first stage, some folks like a long one. The choice is very much personal!

The second stage is also adjustable for weight and length of movement. Weight of the 2nd stage is set the same in manner as the first stage, by increasing or decreasing the compression applied to a coil spring. Since the Steyr trigger is quite crisp the pistol normally fires after only very little, almost imperceptible, movement of the trigger occurs. Thus movement of the trigger occurs after the shot fires, and is called 'overtravel'. Some folks like the trigger to continue to move after the shot fires, while others (myself included) like the trigger to move very little after the shot breaks. One needs to be very careful in adjusting the overtravel because if we adjust it so there's no movement after the shot fires there's a good chance that with temperature change etc we will get ourselves into a position where the overtravel stop my be adjusted so short that we can't move the trigger far enough to the rear to fire the shot. Obviously this would not be a good thing to have happen in a match!

As for general rules of thumb on trigger adjustment, we need to be able to support a 500gram weight on the trigger. Most of us like to have somewhat more than this to give us a margin for error (I personally run 520-530 grams on mine). The weight is often split 50:50 between the stages, or something close to this. I personally favour a slightly different split, with about 400 grams on the first stage, and the remaining 120 or so grams on the second stage.

Hope this helps!

[John Harvey]

Hi Mark - it has helped - enormously, thank you. Now for the first time I have the understanding of how the first stage travel corresponds with the first stage weight. And, yes, writing this from Bali where as you are probably aware the coldest it ever gets [June/July/August] is 23'C nights and 28'C days. Mind you, that's why AP is the way to go here with ranges that are air conditioned. Anything outside - shade or no shade is just far too hot.

[wasatch]

Hi John and Mark,
Thanks so much for your thread! Thanks Mark for your explanation of the trigger stages. After reading it, seeing those nice trigger force-displacement charts in Visier and reading other posts where someone says their trigger was tuned to 420g 1st stage and 100g 2nd stage (roughly made up numbers) I was left wondering, "well how am i going to quantify my trigger to set it up mirroring these settings other people are using?"

But then I started thinking I shouldn't be trying to set this or that weight for the 1st and 2nd stage specifically... Should I instead setup my trigger with as little 2nd stage as I can reliably & safely control and then turning up the 1st stage so in total the trigger can support at least 500g consistently? With better trigger control, should I want to further reduce the amount the 2nd stage takes up of the total pull? Would that be the objective?

Out of the box my K12 trigger was close to but wouldn't quite support 500g (weighed pellet tins support by a coat hanger) so I only turned up the second stage till it supported ~520g. So most likely my 2nd stage is set higher than need be especially since I felt like i could control the trigger out of the box before turning up the 2nd stage.

One of many :-) things I don't understand is when people talk about 2nd stage roll. Does roll mean 2nd stage movement that isn't sear creep? Why is that desirable by some?

[Gwhite]

On a vaguely related note, you don't want too small a second stage pressure increase if you ever have to shoot when it's cold. I also shoot highpower rifle in a spring league in New England. I've been dry firing for weeks in my warm basement and really liked my new trigger set up, with just over 1 1/2 pounds on the first stage, and about half a pound for the second stage. However, when I shot outside (temperatures around 50F), I frequently found I couldn't feel the 2nd stage distinctly, and occasionally pulled right thought it, resulting in a couple of 8's.

I've had similar issues shooting air pistol on cold ranges, and shooting free pistol outside in the spring or fall. As soon as your hand gets a bit cold, the sensitivity in the tip of your trigger finger is one of the 1st things to go.

[william]

"...occasionally pulled right thought it, resulting in a couple of 8's."

In my case the 8's would be a welcome relief from the 7's & below ;-)

[wasatch]

I tried this approach and now the trigger of my K12 is really nice. 2nd stage is much lighter while still being controllable. 1st stage doesn't feel terribly heavy. Nice how it works that the final release is lighter but it still holds up 520g!

I wonder tho how people are able to accurately measure 1st and 2nd stage independently... by just watching a digital pull gauge and noting the weight when motion stops at the end of the 1st stage travel and then letting the device record the max pull when the 2nd stage releases?

[David Levene]

I wonder tho how people are able to accurately measure 1st and 2nd stage independently... by just watching a digital pull gauge and noting the weight when motion stops at the end of the 1st stage travel and then letting the device record the max pull when the 2nd stage releases?

I did it by mounting the gun in the chuck of a (disconnected) lathe and a Correx gauge on the carriage.

I didn't give a damn about the split between 1st & 2nd stages, if I liked the feel then it was right.

I did it to see the reduction in trigger weight on a mechanical trigger when it released.

[wasatch]

Well I tried reducing 2nd stage while increasing 1st stage and at first had something I couldn't control reliably so iterated a bit more till i got something i could control. Did a couple of dry fire sessions earlier in the week and shot last night. My horizontal dispersion decreased and ability to call shots went up! Quite happy with result :-)

[David M]

Do not go too light on second stage. 80-200g range is controlable
and should stop trigger grabs, also it will help with nerves, finals and
cold weather feel.