Brno ZKM 455S Model 3 Stecher Trigger Pictures - RimfireCentral.com Forums

Go Back   RimfireCentral.com Forums > >

Notices

Join Team RFC to remove these ads.
Reply
 
Thread Tools Display Modes
  #1  
Old 10-16-2019, 10:00 PM
jmrybak is online now

Join Date: 
Dec 2010
Location: 
Memphis
Posts: 
1,239
TPC Rating: 
100% (3)
Talking Brno ZKM 455S Model 3 Stecher Trigger Pictures



Log in to see fewer ads
Hello all,

I am posting these photographs here as a reference for those possessing or interested in the Brno ZKM 455S Model 3 Stecher, and in particular its trigger assembly. The photos of internals below are courtesy of Lakeside Machine, the brave man who took a peak inside. Hahah

He describes the assembly as:

Quote:
The trigger units I have looked at all look like short run items, more like prototype stuff yet small batch products.

They all are hand polished and fit. It would be a B*#ch to make another internal part as they are small, heat treated and fit to interact with the other internals. There are just three moving internal parts plus the two triggers. The front being more of a cocking lever than a trigger, the rear is the actual sear caught trigger.

There are two springs inside the system. One is the rear trigger coil spring which is a simple and common spring to replace. The other is the flat visible on the outside of the trigger unit. This one is tougher to make as it is slit/split and heat treated for its compression feature. If this one would crack, that would be no fun to remake.

The overall system is very robust and I feel should be long living with normal use.
The first picture is when the trigger system is “set”. The part that looks like the top end of a question mark is caught on the trigger sear.



The second picture is when the trigger is fired.



The square window on the left side of the picture is where the split flat spring is inserted into to give the “hammer” portion of the trigger its power.



And here are a few photos of the assembly attached to the action.



Compared to the Brno ZKM 455 Model 3 Standard



With the stock




Last edited by jmrybak; 10-16-2019 at 10:10 PM.
Reply With Quote
  #2  
Old 10-16-2019, 10:37 PM
jmrybak is online now

Join Date: 
Dec 2010
Location: 
Memphis
Posts: 
1,239
TPC Rating: 
100% (3)
Talking

Here is something Zdenek "Denny" Jakubec hiself sent me a while back regarding the Stecher trigger

Quote:
The Stecher mechanism is very precise watch like mechanism and very sensitive to tinking with it

So if ZI can advise you do not remove Stecher box from rifle unless is broken..

The Stecher adjustment is done via small screw accessible with fine screwdriver through hole in the trigger guard.

If you need to adjust trigger – do the screw turn in very small increments. There is small range of adjustment

And you will feelwhen you over done it – Stecher will discontinue function and you have to go back to re set.

Also, when Stecher is turn too light – rifle may mis fire – so be carefull about it.

Please do not lose that small Stecher adjustment screw !!!!! Apply drop of removable Loctite

To screw thread – so it stay in place.

Please see attached scketch of how to re set Stecher in case it gets disengage during removal.
Reply With Quote
  #3  
Old 10-16-2019, 10:40 PM
I6turbo's Avatar
I6turbo
NRA Member - Click Here To Join!

Join Date: 
Apr 2012
Posts: 
3,392
TPC Rating: 
100% (5)
Very interesting! Thank you to you and Lakeside Machine for getting these photos and the comments up.
Reply With Quote
Sponsored Links
Advertisement
 
  #4  
Old 10-17-2019, 07:01 AM
gmd1950's Avatar
gmd1950
US Air Force Veteran Law Enforcement Officer NRA Member - Click Here To Join! GOA Member

Join Date: 
Dec 2006
Location: 
Mebane, NC
Posts: 
52,985
TPC Rating: 
100% (29)
Very good information, thanks for posting.
__________________
https://mostlyrimfire.com
NRA Patron Member/GOA Life *Esse Quam Videri Ya'll*
Reply With Quote
  #5  
Old 10-17-2019, 11:13 AM
Lakeside Machine

Join Date: 
Apr 2010
Location: 
Arkansas
Posts: 
266
TPC Rating: 
100% (3)
Clarification on the drawing for those interested.

The hand drawn image is depicting a method to re-engage the trigger internals if they ever get out of place. There is a sequence that needs to be followed if the hammer, center fulcrum(middle piece), and sear get out of position. This can happen when the trigger unit itself is removed from the rifle and the hammer can over rotate and disengage with the fulcrum arm (middle piece). Once the FA over rotates, the the sear can come up of place too......it all must be reversed in proper order to get them all back in position again.

So again, the drawing does NOT depict the actual function of the trigger group. It doesn’t make sense if you try to visualize the arrows in working movements. This drawing shows how to re-engage the trigger parts if they get out of position.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off




All times are GMT -5. The time now is 12:23 PM.

Privacy Policy

DMCA Notice

Powered by vBulletin
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Search Engine Optimisation provided by DragonByte SEO (Lite) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©2000-2018 RimfireCentral.com
x