SUB2K Reset Issue

#81

Just put the new trigger bar in mine last night, and came across the same issue. Got up this morning and put one mag through it with no issues. Seems to be the same thing going on with mine too, no reset when doing a function check but operates perfectly when live firing.

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#82

Maybe there’s a “new normal” for the function check with the MCARBO trigger bar. LOL

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#83

@Kona … thank you sir. I will be creating extra clearance there before putting mine back together. I’m thinking a couple thousands off via wet sanding should do me, but I bet I end up coating there and the trigger bar with dry lube as well.

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#84

@Dred I think you’re right. It seems like if it were much more we would be seeing more issues for sure.

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#85

I tried to find a “dead spot” in the trigger reset but it maintained tension throughout. I also tried letting out the trigger slightly while charging. I’m not sure how to “force” a dead reset. When it does happen I’m at a loss for what caused it.

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#86

Lol! Maybe so! This is the first time I’ve ran into an issue like this

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#87

I wonder what issues we might have down the road from all this dry firing. IMO, Kel-Tecs aren’t that robust in the first place and I’ve had parts break before, including a firing pin.

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#88

@Wedge A horrible side effect of new springs I went from 3.5ish lbs to 6.7ish lbs trigger pull. This thing needs all the dryfire it can take. Ha!

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#89

I’d rather have a little bit heavier trigger pull instead of light strikes from a worn out hammer spring, though. LOL

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#90

Most of my gunsmith experience has been with bolt action rifles and the AR platform. With bolt actions I always hold the trigger when closing the bolt on an empty chamber so it wouldn’t have to be dry fired to uncock. In boot camp we were taught to NEVER dry fire an AR (M16). If it was cocked on an empty chamber and needed to be decocked we were to pull the charging handle back half way and pull the trigger while slowly allowing the charging handle back forward. In the old days dry firing was frowned on so I guess I still have that mentality.

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#91

Mine came in yesterday. And starting to set up for change out some time tonight. Just function checked and will do so again before and after change out. Will caliper check both old and new like some asked here and thinking I may put some dry lube or graphite in the area to see if that changes out come.

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#92

It’s a good thing that their firing pins are relatively inexpensive…

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#93

I’ve gone through all 8 SUB’s and 20 different Trigger Bars since this morning and have validated the issue and solidified the solution.

I was able to replicate the issue and also managed to replicate this issue by charing really slow with the OEM trigger bar. If you don’t put enough force/strenght into charing the bolt it’s possible to induce a malfuction and even successfully induce a few with the OEM trigger bar.

That being said there is a slight flaw in the trigger bar design that could prevent it from passing the last portion of the 3 part function check. It’s not all the time but can be induced by the user not charing hard enough or short stroking the charing handle. Either way it’s not what we intended or wanted either…

Problem: Sharp Tip is grabbing bottom of tip on sear.

Solution: Remove sharp tip.

Use 1,000 Grit Silicon Carbide - avilable at any hardware store or harbor freight.

Put CLP or Gun Oil on Silicon Carbide Sandpaper to wet sand the sharp point.

This will take roughly 15-20 minutes to throughly remove sharp tip.

If your not confident doing it yourself we can do it for you. Just send me an email. chris@mcarbo.com

Let me know if you able to try it and report your results back here. Eager to hear this. I hope it helps!

I konw it worked for me. I literally spent all day on this. Glad we can make forward progress and get the results we all expected.

Thank you for your patience and support!

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#94

Video to follow here in a few minutes

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#95

No this is fun. This is why I signed for this forum and not others. I’m excited to be on the front line of something radically new, I’ve watched and listened as the guys ran through this. Wow! What a resource!! For you and me.

Proud to be among ya’s👍

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#96

Don’t have time to try the fix this weekend. Top of my list for next week.

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#97

Thanks Chris. It’s because of your dedication and the brotherhood I saw here on this forum that made me feel confidence in using MCARBO parts. After I get done with my batch of reloading I’m working I’m gonna try your fix. Looking at your photo, it looks like about a 1/32 chamfer you put on there. Would you say that’s correct. Hard to tell for sure just Looking at the photo.

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#98

Thank you very much. Was just tinkering with mine before putting it in and kinda wanted input of how rounded to make it. Because from your picture there it seemed like a good bit of material removed. Going to wait for video before proceeding and maybe do it in stages.

Edit maybe it is the angle of the pictures that makes it appear to be more then I was thinking any way to get a close up straight on shot of before and after.

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#99

No easily available firing pins available for modern pistols are “expensive”, but that’s not the point on having one fail on you. :wink:

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#100

@ChrisNelson How critical is rounding that corner? Is it possible that just a smidge too much metal be removed and cause other issues? As for me, since mine actually fires just fine, I’ll leave it alone and “long term” test and see if anything happens down the road. I won’t even round off the corner if I have to go back inside mine for whatever reason.

1 Like