M*CARBO Brotherhood

Malfunction in New MCARBO Modified Gen2

Hello Good Folks of the Brotherhood, last night I installed a variety of MCARBO parts into my new Sub2000 9mm Gen2. Mods included the new Performance Trigger Bar, the Flat Target Trigger, and the MCARBO Spring Kit. I am having two issues now that I could use some insight into. First, when I pull the bolt back and let it down gently the hammer cocks fine, but when I pull the bolt handle all the way back and release it, or when I lock the bolt handle in the bolt tube and release it from the slot (in other words, allowing the bolt to slam home), the hammer either does not cock or it does not remain cocked. I have not shot the gun to know if it would automatically fire when the bolt is pulled back and allowed to go forward with full force, but I don’t want to find out. Any idea what may be going on?

The second issue is that the trigger still has a lotttttt of creep to it. The trigger pull is much lighter and the release is crisp but it is very creepy on its way to the release…

Thanks and best wishes.




There is a MCarbo Thread on your concern and I believe @kona provided a video in which he had duplicated the ‘hard reset’ after 15X’s. The group census was to just go out and ‘shoot it, first!’ No one likes to question their ‘mechanical abilities?’ Happy shooting and welcome to the MCarbo Brotherhood~


@Streamside Welcome to the Brotherhood. Don’t forget to go to the First Post Here: Introduce Yourself! thread and say Hi to everybody.


@Streamside welcome to the brotherhood kevin

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@Streamside mcarbo took a pile of junk stock trigger and made it less of a pile of junk. You’re not pulling a Geissele brother. One of my subs had no creep, the other was mush. :man_shrugging:t2:


Slowly, very slowly and stop. @Streamside described hammer follow - as in, the sear is not reliably catching the hammer. This is very different from an unreliable reset. Please get it solved before she runs away and dumps a mag on you.

@Streamside - open her back up and pay careful attention to all things sear related. If you fire it, start with a single round on an empty mag then slowly work up to a couple rounds in the mag. Do be prepared to control a burst if your sear isn’t catching the hammer.



COWABUNGA, DUDE… ‘Surfs up?’ :grinning: Thanks, guess I was cruising the web too quickly, for sure! :+1:

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Thanks for the great input, gentlemen. I have not been able to duplicate Kona’s hard reset, so I do believe it is an issue of the sear not catching the hammer when the bolt throws hard. I’ll give MCARBO a call to inquire if they have encountered this before.


I called MCARBO and they said it was either that the “middle” grip screw was too tight or the hammer pin / bushing was not pushed in fully. Turns out the problem was with the depth of the plastic bushing on the hammer pin. I removed the pin and reseated the bushing. Problem solved. Man I hope MCARBO comes out with their stainless hammer pin bushing soon…