mechanics of LP10

scerir · Post by **scerir** » Fri Dec 10, 2010 6:34 am

On page 39 the manual describes the first stage travel adjustment (see figure 6.4).

http://www.steyr-sportwaffen.at/media/L ... 0_c_en.pdf

Now, it is well known that if you turn that screw (having removed the trigger-stop), you also change the first stage weight, for obvious reasons.

What (to my knowledge) is less known is that if you turn that screw, clockwise or anticlockwise, you also change - substantially - also the second stage weight.

In my opinion that is because you change the leverage point, that is to say you somehow change the point of 'impact' of that screw on the 'trigger lever'. The 'feeling' of the trigger action (second stage) changes completely. You can make the second stage feeling 'shorter' or 'longer', and 'heavier' or 'lighter', turning that screw (and without touching the sear engagement screw at all).

Is all that correct?

LukeP · Post by **LukeP** » Fri Dec 10, 2010 7:35 am

So moving that screw 1mm far away, change the leverage significantly? It moves during an arc of movement so short i think it's barely noticeable.

To esamine the entire question, ask yourself what add pressure to the sear engagement... only the screw? Not only, it's also the velocity screw, behind the pistol: that spring push directly on the sear; change it, you change both weight and travel of the sear engagement, i think of the same barely noticeable quantities.

scerir · Post by **scerir** » Fri Dec 10, 2010 9:47 am

LukeP wrote:So moving that screw 1mm far away, change the leverage significantly? It moves during an arc of movement so short i think it's barely noticeable.

From what I (and others 4 shooters here in Rome) see, it changes the point of leverage significantly. It changes the feeling of the second stage. In certain cases (here) people cannot 'control' properly the second stage if the travel of the first state is too short (of course having readjusted the weight of the first stage to - say - 350 grams).

LukeP wrote:To esamine the entire question, ask yourself what add pressure to the sear engagement... only the screw? Not only, it's also the velocity screw, behind the pistol: that spring push directly on the sear; change it, you change both weight and travel of the sear engagement, i think of the same barely noticeable quantities.

Of course. But when all these parameters are fixed, and you change only the first stage travel (turning clockwise or anticlockwise that screw) that changes the weight, and the feeling, of the second stage. So, apparently, the only possible cause is the changing of the point of leverage on the trigger lever.

Notice. If I remember well, but I'm not sure, the ooold Steyr LP - not the LP1 - did not have any regulation of the weight of the second stage. But it had a weird screw (in Italian: una camma) which was regulating exactly the leverage point on the trigger lever.

scerir · Post by **scerir** » Fri Dec 10, 2010 10:19 am

scerir wrote:If I remember well, but I'm not sure, the ooold Steyr LP - not the LP1 - did not have any regulation of the weight of the second stage. But it had a weird screw (in Italian: una camma) which was regulating exactly the leverage point on the trigger lever.

Found something on http://www.pilkguns.com/tenp/default.htm . Search for 'Steyr' and then 'LP1 pistol - first model'. See the figures 'variant 1' and 'variant 2'. Maybe the present first stage travel screw is somehow 'reminiscent' of that old system? :-)

ghostrip · Post by **ghostrip** » Fri Dec 10, 2010 10:28 am

Interesting. I also had to revert to a longer than i wanted first stage for my lp10. it made the trigger feeling a lot better.

LukeP · Post by **LukeP** » Fri Dec 10, 2010 6:18 pm

Interesting.
I shoot with a Steyr lp10, maybe i didn't make only one adjustment at time so i was not able to notice the change in the second stage feeling, because i change too much the characteristic of the trigger.
Yes, interesting the Camma of the first model.

scerir · Post by **scerir** » Fri Dec 10, 2010 6:47 pm

BTW, a friend of mine, here in Rome, removed the first stage spring, from his LP1, and used a new long spring attached, in front, to that sort of trigger guard and to the end of trigger tongue directly. What is interesting to say here is that the feeling changed completely. The trigger of the Lp1 became smooth, 'material', calm, something like the trigger of the old Pardini K60.