Sig P220 srt install question

[Sohum63]

Posted here instead of the gunsmith section in hopes of more eyes, hope it is ok.

I have a couple p series sigs and have done some minor changes (springs, trigger and srt kit) in a few of them with no problems. I recently got a new p220 combat and put a hundred or so rounds through it with no problems before attempting to install the short reset sear kit I ordered. After the install every couple mags when shooting in single action the trigger would go dead. You could decock it and fire in double action. I didn't pull the grips while the problem was happening but after clearing the gun I pulled it apart and noticed that while the stock sear makes full contact with the trigger bar to trip it the srt sear only has about 50% contact and I am guessing that is ocationaly letting it slide along the side without firing. Is this a problem anyone has had? Could I have ended up with the wrong srt kit? I didn't compare dimensions to any other ones yet.
Thanks for any help

[SkyHawk]

IIRC the P220 SRT is the same as all of the others.

Have you changed the grips? What trigger bar spring does it have, old or new style? New style trigger bar spring is not compatible with old grips, unless the grips are modified.

[Sohum63]

Yes, everything I have found says most of the srt kits are the same except possibly the p239 and some come with a new decocker and some don't. I haven't changed the grips yet I have seen the different styles of springs but I don't think that is coming into play. I may be using the wrong terminology and can't get a picture right now but maybe this one I found will help explain it.

https://www.bing.com/images/search?view=detailV2&ccid=D8aha%2fOP&id=086387C5A937427877983ECD68B7D54807F364FD&thid=OIP.D8aha_OP23WxIERLzx4HLQEsEs&q=sig+p220+trigger+bar&simid=608039088886124479&selectedIndex=29

This is where I believe the problem is, I will recreate it when I am home to double check but here is what I think is going on. This is what it looks like cocked, when you pull the trigger the bar slides forward and the tab on top trips the sear. With the part it came with installed they make full contact but when the srt seat is installed the bar only cantacts it about 50% and the tab is only a few mm wide si I think ocationaly something allows it to get off to the side and pass by. Sorry I can't describe it any better, I will get some pictures and take some measurements when I can. I was mostly seeing if it was something anybody else had experienced. I was worried I had something installed wrong or somehow bent something but I have switched stuff back and forth changing only the srt kit and have no problems with the oe parts and it happens whenever the kit is installed. I haven't looked much closer I figured I would see if it is a known problem before doing much else but I haven't found any mention of it yet.
Thanks

[OCEquestrian]

Home gunsmithing.....

[Sohum63]

Yeah yeah I know lol. Figured swapping one factory part for another should be doable and had good results before. It's back to the way it came for now until I can get a solid answer on what is going on. Thanks

[billped]

Swapping OEM parts doesn't bother me, it's the untrained (or YouTube-trained) guys with files and dremels that cause me issues - some are awesome and some are ...not.

[OCEquestrian]

Yeah yeah I know lol. Figured swapping one factory part for another should be doable and had good results before. It's back to the way it came for now until I can get a solid answer on what is going on. Thanks

Swapping OEM parts doesn't bother me, it's the untrained (or YouTube-trained) guys with files and dremels that cause me issues - some are awesome and some are ...not.

[jimmythebrain]

problem is probably the spring that holds the trigger transfer bar up. on the P220 it is just a bent wire, no round loop in the spring.
I installed a SRT on my P239 that had the new spring and I got it confused with the weaker used/original factory spring. I had the same problem until I installed the new, (possibly stronger?) spring.
The P220 SRT kit does not come with a new spring. As a result you may have it hooked under the wrong part of the bar. if your gun is NEW then it should have a strong spring, if your gun was bought used or CPO you way want to buy a new trigger bar spring.

when the spring is weak it lets the trigger transfer move ever so slightly out to the side and it misses contact with the sear leg...equals a dead trigger.