Broken trigger

[JamesT]

I'm trying to figure out why my trigger broke so I dont make the same mistake again. I read through a few threads on trigger making in the tutorial section and found no mention of hardening or tempering. For the triggers themselves anyways.
I used a store bought single phase double trigger and reshaped to suit me. The rear trigger I heated and bent then filed on. I was testing them and after several times when I touched off the front trigger the rear one broke.

I am assuming it had to do with heating it. I was only heating where I wanted to bend it not the entire piece. Is this the culprit? Looking for some of advice so as to not repeat this again.

James

[Ross Dillion]

I believe those triggers are probably cast steel. Reshaping it probably created some cracking.

[JamesT]

Hmmm. You are probably correct on them being cast. Looking at it there are also file marks that could create stress risers too. So would my best bet be to try and make a replacement from scratch? Do I need to harden it? Wishing I would have had that nice set you made to begin with Ross😃. Maybe on the next rifle!
James

[Elnathan]

Did you bend it while it was red-hot, or did you heat it to soften it and then bend it cold? Either way, I'd guess that it wasn't hot enough when it was bent and so cracked, then the repeated shock of striking the sear lengthened the crack until it went all the way through.

If you weren't heating the whole trigger, then it is possible that the crack formed at the heated zone, where it wasn't hot enough to be completely plastic yet there was still stress being applied.

[P.Bigham]

When I modify triggers I cut or grind off the trigger then forge a nail to the shape I want then silver solder to base of the trigger. 

[Ross Dillion]

Hmmm. You are probably correct on them being cast. Looking at it there are also file marks that could create stress risers too. So would my best bet be to try and make a replacement from scratch? Do I need to harden it? Wishing I would have had that nice set you made to begin with Ross😃. Maybe on the next rifle!
James

You could make a replacement and put whatever curve you wanted in it. You can’t harden mild steel which is probably what you would be using. I guess you could use some O1 oil hardening tool steel and then bring it back to a spring temper but that would be overkill IMHO. I use mild steel for my triggers and then case harden the bearing surfaces. I’ve broken several trying to get that deep curl in the rear trigger.   

[JamesT]

Thanks for the help gang. Im pretty sure I did not have it hot enough it seems. I was using MAPP and working it on my vise. I like the idea of soldering on a new shoe from a nail. I wouldnt have to remake what I have for the internals. Can I silver solder it with MAPP ya think? If not it looks like I will be making one from scratch. Thanks again for all the ideas.
James

[msellers]

Thanks for the help gang. Im pretty sure I did not have it hot enough it seems. I was using MAPP and working it on my vise. I like the idea of soldering on a new shoe from a nail. I wouldnt have to remake what I have for the internals. Can I silver solder it with MAPP ya think? If not it looks like I will be making one from scratch. Thanks again for all the ideas.
James

For that small of a part, MAPP should be more than adequate for silver soldering. Silver braze is another story without some major preheating as I understand.
Mike

[Bob Roller]

Probably a cast trigger.Is there any name or logo on ot?
Over the years,more than 50 I have made quite a few
triggers from 0-1 and so far,so good.I don't use it now
because it's priced off the market in some sizes.Low carbon
flat ground is the same way,too costly.

Bob Roller

[Eric Krewson]

I did the same thing on a Davis trigger that wouldn't quite fit my trigger guard bow. I heated it and bent it but had a senior moment and gave it another tweek cold and it snapped in half. I ground the broken ends to a long bevel and soldered it back together until I could get another trigger from Davis.

I got another trigger but it is still in my tool box, my repaired one works just fine.

[JamesT]

Probably a cast trigger.Is there any name or logo on ot?
Over the years,more than 50 I have made quite a few
triggers from 0-1 and so far,so good.I don't use it now
because it's priced off the market in some sizes.Low carbon
flat ground is the same way,too costly.

Bob Roller

Bob,
 This is the trigger I used. I am sure it's a fine trigger and would have lasted forever before I got my paws on it. I'm not blaming the trigger at all. Whatever its made from. I thought modifying a trigger was the way to go because I didnt want to tackle the whole project but now I'm wondering. Ha.
 So I will ponder on it and see if I cant fix it. I will provide an update when I get it worked out. I am making the patch box this weekend and I have to finish the guard as well. There is so much to building one of these things ya know. Thanks for all the help! Some really knowledgable and just good folks on this forum. I am thankful for it.
James