M*CARBO Brotherhood

SUB2000 Tear Down Update

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One USPSA match in the rain and the amount of rust is insane. Doing a deep deep clean and will post MCARBO parts updates as I go. Also switching hammer spring back to OEM and seeing if that fixes the light strikes.

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800ish rounds with trigger bar and it looks brand new. Seriously buy one ppl!

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Lifesaver buffer after 3000ish rounds. Still in good shape.

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4000ish rounds with the 2 finger CH and the outer coating is seriously mangled. CH itself is in good shape.

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MCARBO pro trigger, trigger guard, and extended magazine release all in great shape after 1000s of rounds of abuse.

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@Kona Cut that coating off and get a couple of the grip sleeves to put on. They’re easier on my fingers.

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Cleaned up and back in place. Hoping to make it to range before they close.

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12/60 light primer strikes. I have no idea what’s causing it at this point. Tried 3 different ammos. Blazer factory, federal factory, Hand reloads.

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@Kona Logan have you ever taken the bolt apart? Maybe check for a rough firing pin hole or some gunk built up in there or a weak or broken firing pin spring. Good luck.

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@don68 I’ve never taken bolt apart. Don’t even know where to begin.

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My face says it all after another “click” instead of “bang.” Taking it to my dads now. He’s a retired gunsmith. He doesn’t know jack about Keltecs but he should Be able to figure it out.

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@Kona Neither have I. Exploded view only shows 2 roll pins in the bolt head. I is the firing pin pin and the other is the extractor pin. Get a roll pin punch and drive it out. Maybe someone else has done this.

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I think (hope) I’ve figured it out. Firing pin appears to be in tact and working proper. There was substantial carbon buildup in the bolt channel for the upper feed ramp which could have potentially stopped the bolt from going into full battery. I’ve cleaned it out but won’t know if properly diagnosed until later this week.

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i appreciate the update man. Are you still gonna leave the oem spring in there?

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@airbornetroop206 I’m thinking of just ordering all new springs from MCARBO. I’m going back through old videos and these light strikes started around mid-June. Had 3/60 light strikes today so not nearly as bad as yesterday.

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so do you think the mcarbo springs were contributing to the light primer strikes? i have them installed in mine and haven’t experienced any light primer strikes but then again I probably haven’t shot mine as much as yours.

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I still have MCARBO springs in it. I was hoping the deep clean would fix it. This gun ran for forever with no issues on MCARBO springs. At this point I’m gonna put the OEM springs back in and order new MCARBO springs.

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The top hammer spring is the MCARBO, bottom spring is OEM. MCARBO spring is bulging on the far coil which would indicate a reduction in tension and possibly be the cause of a weak hammer strike. Also the part of the spring on the right that captures the hammer is severely dipping down compared to OEM. If I had to guess I would say that MCARBO hammer spring has 5-6k rounds on it.

Anyone have an opinion about these 2 springs?

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@Kona thank you for all of the detailed feedback and pictures. We appreciate that. Springs do wear out and eventually take a set. In this case it sounds like the springs are so “broken in” that the hammer spring has lost enough spring rate to provide enough hammer energy to the firing pin. I appreciate you trying other brands of ammo as well. That can also be a problem. I’ve seen old ammo cause light strikes.

What is your current trigger pull weight?

Do you remember what you started with after installing the springs? Has it gotten lighter?

Glad to see the Trigger Bar is doing so well! We’re excited to get them released this Friday!

Send us an email to the help@mcarbo.com and we will get you a replacement set of springs. You’ve done a lot of testing for us so we could just say you wore them out during product testing. :wink:

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@ChrisNelson thank you so much. I am so grateful to you and your amazing company. :pray: my current trigger pull weight is around 3.8 lbs. everyone including myself thought that was incredibly light. I don’t remember what it was before. No old ammo. Factory new and fresh Hand reloads. I’ve definitely seen a progression going through old videos back to June as the light strikes slowly began happening more frequently which would also in my mind indicate spring wear. Especially when usual ammo that wasn’t a problem before suddenly was. I will email support for springs. Again, thank you so much and keep up the good work!

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