Friend Az_Speed

Bill Calfee

Gun Fool
Friend Az_Speed


Friend Az and CYA friends:


Since Az asked for a description of the various parts of the DiOrio 3 lever trigger, I addressed the title of this thread to him.


I'm going to attempt to explain some things about how a three lever triggers produces its lightness of pull...


And then some very interesting things about how this relates to the new V-3 action, especially the way I've got mine set-up.


Here's a doodle...


DSC00248%20-%20Copy.jpg



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On a factory Remington trigger, a sear surface about in the middle of the transfer bar contacts the sear surface of the L shaped sear directly...


So you have the cocking piece contacting the transfer bar at the rear, with the pivot pin of the transfer bar at the other end, front, and the sear contact point of the transfer bar about mid way between these two points.


Fulcrum wise, this is like a nut cracker arrangement....


Therefore, if you have a 23# firing pin spring, the actual down force on the top of the L shaped sear may be close to twice that great.


So when you pull the trigger it takes effort to disengage the sear engagement points.......this is why the factory triggers have such heavy pull.


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Then comes the 3rd lever.


If you look at the doodle, you'll see that the fulcrum ratio from the pivot pin of the third lever, to the contact point of the transfer bar, to the tip of the 3rd lever resting on the L shaped sear, is 3.40 to 1............or 1 to 3.40......


Therefore, if we have 23 pounds of firing pin spring pre-load, the actual down force by the tip of the third lever on top of the L shaped sear, is a about 6.8 pounds.


Now, this is where it gets good because of my V-3 having just slightly over 8 pounds of firing pin spring pre-load:


I only have about 2.45 pounds of down force on top of the L shaped sear in my trigger.


Some of you folks should check my math, but, I believe it to be in the ballpark of being correct.



Your friend, Bill Calfee
 
Something I've not done yet...

Something I've not done yet...


CYA friends:


My new MD-PAS triple pistol uses a 10-X action, because it's longer than my new V-3, which makes it work in a factory modified stock, much easier.


And the Bond copy trigger I built for it is awesome....


But...........


I'm having to run the lighter of the two Wilkinson springs it it,,,,,,,


And this spring gives about 20-21 pounds of pre-load.


I have to run this Wilkinson spring, because the 10-X action doesn't give me near as much firing pin travel as the new V-3 does.


Plus, these new V-3's are so amazingly "free".


CYA friends, there's something I've not done yet.



I've not installed my new trigger in my V-3 to see how it works.


And remember, instead of 20-21 pounds of firing pin spring pre-load, my V-3 only has 8# 6 oz of pre-load.



Therefore, what kind of lightness of pull will I have?



I'll only have 1/3rd of the down force on top of the L shaped sear from the tip of the third lever,


So sometime today, I'm going to install my new trigger in my V-3....


I'll have to install a spacer between the action face and the barrel shoulder, or I'd have to alter the length of the trigger linkage......way too much trouble.




Your friend, BC



DSC00248%20-%20Copy.jpg



CYA friends, it's still hard to believe I'm only running 8 pounds of firing pin spring pre-load and producing this kind of footprint with my V-3.


Freeness and .216" of firing pin travel is the secret.



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