Trigger adjustment Hammerli SP20

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Marty660
Posts: 2
Joined: Wed Mar 10, 2021 8:53 am

Trigger adjustment Hammerli SP20

Post by Marty660 »

I am having trouble understanding the terminology of the manual. It describes how to increase the take up weight, increase the let off weight (?) etc.
Then it describes trigger slack force (what does that mean?) trigger slack weight etc...very confusing to me.

I want to decrease the trigger pull weight. I have a manual the shows the screws etc.
Any help is appreciated. (as would be a Hammerli combi tool if you know where I can get one of them)

Thank you
mister G
Posts: 147
Joined: Sun Mar 07, 2004 8:09 am

Re: Trigger adjustment Hammerli SP20

Post by mister G »

Although I haven't had to adjust the slack force, I think it's referring to the slop force to move the trigger until it first engages the hammer release. I call it take-up force.
My Special Tool, part 1.309.260 is under lock-and-key and almost never sees the light of day. (LOL). I could provide pics and dimensions, but it's NFS. Sorry.
David M
Posts: 1676
Joined: Wed Mar 24, 2004 6:43 pm

Re: Trigger adjustment Hammerli SP20

Post by David M »

trigger group.jpg
trigger group.jpg (32.23 KiB) Viewed 2721 times
The Hammerli 280 and the SP20 use the same trigger cassette.
Screw 8 is the first stage weight on the sear bar.
36 is the co-axial 2nd stage unit, 29 (inner) is the 2nd stage weight and 36 (outer) is the 2nd stage position or point.
15 is the sear bar travel used in conjunction with 28 trigger forward travel to set transfer bar clearance for trigger reset.
28 is the trigger overtravel stop.
To increase trigger weight on 1st stage screw 8 in clockwise.
To increase 2nd stage weight use inner allen screw 29 in clockwise.
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