Changing Radius of Recurved Triggers

[75Plus]

I picked up a couple of used SP-01 triggers to experiment with. The radius from the factory was 10mm. The same as in my 08 polished stainless CZ 75. The trigger was a snug fit around a piece of 20mm dia. round stock. I found that the radius of the trigger in my 07 production Kadet pistol and my 06 production CZ 75 was 12mm which was a good fit around a 24mm dia. round stock.

I decided to see if the radius could be opened up without damage to the trigger. I selected a 1 inch diameter socket from my tool box and went to the arbor press. The trigger was centered over the socket and under the press and pressure was slowly applied. When released the spring back closed the radius back to the 12mm I was looking for. Close inspection of the trigger showed no damage from the operation. I polished polycote finish off so I could use the trigger in  my SS pistol. The pictures show how the radius was changed. This may be a way to eliminate the trigger bite some members are bothered with. It will also shorten the reach slightly. The older triggers are thicker than this newer one but the radius on the finger side is the same

[1SOW]

I really like practical solutions to annoying problems!
Very slick.

[Stuart]

Nice work.

[tdogg]

Ooh, I'm going to try this!

Did you see a single spot or multiple spots where the trigger opened up at or did the entire radius match the socket?  Did the polycoat survive the process or did it crack?

Cheers for the good idea!

Toby

[Joe L]

That's a good modification, 75Plus. 
Joe

[75Plus]

Ooh, I'm going to try this!

Did you see a single spot or multiple spots where the trigger opened up at or did the entire radius match the socket?  Did the polycoat survive the process or did it crack?

Cheers for the good idea!

Toby

Toby the radius opened fairly linear as can be seen in the new pictures. The finish is actually oxide not polycote and there was no cracking. You should press at the thickest part that you can. Hope these pictures help.










 

[tdogg]

That's awesome!

I have a spare trigger to try this on and I am going to!

Cheers again for the good idea!

Toby

[Towns]

The pictures make a very good demonstration.  Thanks!

[Googe1227]

Nicely done as always Joe!

[tdogg]

Well I just got done straightening my recurve trigger.  I have an old style 85C trigger on my SP01 and used it as my target radius.  It fit my 9/16 inch deep well impact socket (diameter 0.968 inch).  So I took that to work with me to use as a guide.  I definitely had to go up a socket size or two to account for the spring back post press operation.  But the recurve trigger now has a nearly identical radius as my old style 85C trigger.

The finish on the face of the trigger has a couple of small scratches from where the trigger rubbed on the socket.  I think in the future, I will put a piece of paper inbetween the socket and the trigger to try to eliminate the rub marks? 

Now the questions is what gun do I want to put it on to test out the feel?  I think I'm going to put it on the 40P.

Thanks again 75Plus for this great idea.  I will post up how it feels when I get some trigger time with it.

Cheers,
Toby

[mkd]

tdogg! instead of going up a size or two in sockets use the 9/16" and use cardboard to make up the difference in size!

[tdogg]

tdogg! instead of going up a size or two in sockets use the 9/16" and use cardboard to make up the difference in size!

Yeah, maybe I will try to use something a little thicker and tougher like cereal box cardboard?  I have a feeling that I may be doing this mod to all my triggers.  Heck I may even try to drill and tap a set screw on one to put an over travel limit similar to the 85C.

We'll see how it feels.

Cheers,
Toby

[twowheels]

I wonder of you could do this using a heavy duty vice?

[tdogg]

I bet you could.  I used a fairly large arbor press and while there was some resistance I wasn't hanging off the press handle to get it to trigger to flatten out.  Definitely wouldn't be as easy as it is with the arbor press though.

Cheers,
Toby

[1SOW]

With the vice,  maybe adding a little heat would help?