M*CARBO Brotherhood

Screwed up my sub 2000 rebuild

So I broke down and bought the 234.00 kit. I watched the step by step video. Watching sometimes two or three times. I polished everything they said to polish. I had debur the hole in the round trigger bar to get the pin in. However, I used the black 380 glue on the screws because that’s all that was in the package. I don’t know how it will effect anything. My other screw up is that when I put a magazine in, it doesn’t slide nice and the bullets will not feed into chamber. The other changes I made where to the bolt cover. I use the Midwest industry optic mount because it sits flush, so trimming was needed to bolt cover. I also had the mcarbo butt stock but replaced it with a softer (Hey I’m an old gramma) easy on off from missouri tactical. I’m not sure what to do about the not feeding the ammo. One other thing, I got no shim washer for trigger. What did I do wrong?



Here is another thing I struggle with this new mag release looks like poo!


One more thing my small magazine that came with the gun keeps falling out. ARG!!!


So, the main problem seems to be the mag catch - your magazines aren’t locking in, so of course, they won’t feed. Did you get the correct mag catch? My Glock catch doesn’t have holes on the right side but I’ve never handled any of the multimag versions. Does the mag catch move freely, no hangups? Do magazines slide in but not catch, or just won’t insert all the way? Does the action function okay otherwise - hammer cocks, falls when you pull the trigger, trigger resets, bolt goes all the way into battery? Have you looked in the mag well to see if something is out of place and keeping magazines from inserting all the way?

The shim washer isn’t essential, it’s to help take up some side-to-side slack in the trigger. M*CARBO would send you another one but taking the gun apart just for that probably isn’t worth it. Trimming the collar is no big deal - a replacement from Keltec is only around $8 if needed.

I’m just thinking off the top of my head (OWWWW!). I’d bet it’s something simple you’ll figure out and slap your forehead over. At least you got yours together first try - when I did mine the first time, I forgot to put the barrel assembly on and didn’t notice until I had it almost all back together. DOH!


All the magazines worked before the rebuild. They slide in but not as nicely as they did before and they don’t eject smoothly either. The mag catch works well when I push the button with no magazine. Its only the 15 round mag that doesn’t catch and keeps falling out. yes, the hammer cocks and falls when I pull trigger. Battery? Thats greek to me. Haha. Oh damn Im glad I watched that video over and over and took a week to do it. Little bit at a time. Maybe I have the wrong mag release. It doesn’t tell which one to order and what those things mean. Eek


@Jsytsma I’m going to take a wild guess and say that you have the Glock 17 or 19 version of the sub because of the metal collar on the receiver tube. If that’s the case then you have the wrong magazine release installed. Need the Glock one.


Oh damn! You are right. I have the metal collar and ordered multi mag. Crap!


In battery means the bolt is all the way closed. The gun MUST not fire if the bolt is out of battery - that’s double-plus ungood and someone, probably you, could be hurt. Preventing out-of-battery firing is one of the jobs of the trigger bar which also acts as the disconnector. Not only does it fire the gun, it also prevents the gun from firing by unhooking the trigger unless the bolt is all the way closed, and allows only one shot per trigger pull,

When you fire, the trigger bar catches the sear post and pulls it forward, which releases the hammer, which fires the round. The bolt slides back, pushes the disconnector (the trigger bar) down, the sear post pops into the top part of the notch in the trigger bar, the hammer is cocked, then the bolt slides back into battery. This would allow the trigger bar to move back up except the trigger is still pulled and the sear post is still in the upper part of the notch in the trigger bar. When you release the trigger, the bar moves backward and pops up when it moves past the sear post so it can again pull the sear post when you pull the trigger. You hear a ‘click’ and you’re ready to fire again.

The picture below may help visualize what’s going on.


Nice Job on this Explanation and Photo’s for Our Latest Senior
Grandma packing Sub2k’ :smile:


ok, your picture

Ok, I see a mag release that did not have the mag catch installed. Look at your original mag release. Two screws hold the mag catch. Remove the catch from KT release and install onto MCARBO release.. Ok, I see you installed a multimag mag release in a glock sub. The fix is to order and install a glock mag release or reinstall the kel tec glock mag release.

Related trivia. The reason these parts work as glock versus the world results from Gaston’s extra wrist bone that resulted in that wildly unique glock grip angle. Other manufacturers build pistols to point naturally for the common man so there mags all feed at compatible angles. Gaston did his own thing so his mags feed very differently.

Also, I strongly suggest you remove the 380 from the grip screws completely before reattaching them. Hopefully you have steel pins and steel screws and GOOD drivers so you can dissasemble without drilling out stuck aluminum. No loc tite recommended or required for these screws. Blue might be appropriat for fixing the mag catch o the mag release due to limited thread engagement.

Finally, from another picture, I see you are using the MI mount. If you move the optic closer to the muzzle you can ditch the silly cord without risking optic damage. If you do this check out forend stabilizers offered by Performance Services (duckduckgo). I’d add the stabilizer even if I did not move the optic. Some folks have success with MI mount; others never achieve a repeatable zero.

May the reassembly gods bless you.


Thanks everyone for your input. It was helpful!


For what it is worth. I installed all the parts EXCEPT the MCarbo oversize mag release. I AM A LEFTY, the oversize MCARBO mag release is a great way to get a LEFTY killed, it will make it much easier to get the mag to release when you do not want it to.


I too watched the install video like 5 times before my install yesterday. Also had it playing on my iPad Pro hitting the pause button after I completed everything that was explained to me. Good luck on the install. Aloha from WA.