M*CARBO Brotherhood

SUB2000 Upgrades: What Have You Installed & What’s Your Opinion?


Is your Magpul AFG OD Green??


Box said FDE Green. The slight color difference doesn’t bother me too much


A .30 cal A-1 style birdcage drilled out for clearance for the .40 S&W, generic 45 degree rail mount from ebay selected because it still allows for folding and it almost closes enough to latch and a Holosun red dot. This setup is perfect for me as rolling the S2K 45 degrees to the left aligns the but stock to my shoulder and arm perfectly. Also I do not have to remove the mount and red dot to fold it up. Will do the MCARBO mods when I get all the parts in. Voodoo tactical case and mag pouch, fits perfectly.


Hello brother not sure our paths have crossed yet, Welcome to M*CARBO! Nice to have you. Cool setup you have there. Thanks for all the pics. :+1:


Thank you for your welcome. I am glad to be a part of the brotherhood.


Add the KelTec brass Recharge Bar


@Turmeric1 how do you like that part? I thought about it to slow the cycle rate down but went with the MCARBO heavy charging handle instead.


@johnksg how do you like that part?
Mcarbo parts for S2K .40 Glock grips.
Flat Mcarbo trigger
Mcarbo trigger guard
Polished everthing I could. 2lb 12oz trigger that is soooooo smooth
Mcarbo Feed ramp
Mcarbo Heavy recharge handle
Mcarbo Recoil buffer
Mcarbo muzzle break
RSM collar and sling mount
KelTec heavy recharge bolt
Viridian green laser
Primary arms AMDS

Soon to be Blitzkrieg Tritium dot with luminescent green w/tritium dot front sight. Post is out of stock.
I called and talked to Brian this afternoon. He said he just took delivery from his fabricator and it is to have what I want !!!
Which part are you talking about ?
With all the parts I shot these today.
the upper left group was from a person that owned a S2K 9mm. I let him shoot that group out of curiosity and he did that cold !
The center is my <3 sec burst.


@Johnksg Why not combine them ? I did and here are the results as of today


John, I have not timed my cycle rate but I do know that the felt recoil was reduced by the oversized recharge handle and the recoil buffer significantly . I just got the KelTec heavy recharge bar on Friday. It was even a noticeable additional decrease.


The KelTec heavy recharge bolt decreased felt recoil just about as much as the heavy charge handle and Buffer did(both of those separately). In combination with the Muzzle break very very little recoil. I let another S2K (9mm)owner shoot it today. He was amazed. He shot the upper left bull in the othe post i just did.


Hey everyone, I ordered several upgrades on Friday and received them today. Thanks for the lightning fast shipping M*Carbo!!
I spent a little over an hour installing the all in one trigger job bundle, new rear sight, recoilless charging handle, buffer and bolt tube cover. The videos online were exactly what I needed and answered every question I had during the installation. I don’t have a trigger scale but there is a night and day difference in the trigger pull from what I had originally. Everything fit perfectly and worked as advertised. I can’t wait to get it out run a few rounds through it with all the improvements in place. I’ll let you know how it goes!


The metal rear sight. 100% improvement


I was finally able to get a little range time yesterday and I am extremely happy with the upgrades I installed. The rear sight is an amazing upgrade! It allows for a more comfortable position instead of having to get such a deep cheek to stock weld with the OEM sight. The machined peep also allowed me find the front sight post a little easier. All that in conjunction with the bolt tube cover makes the overall shooting experience much more enjoyable.
The all in one trigger upgrade kit is great! The trigger is much more crisp and has a clean, consistent break every time. I don’t have a trigger scale but it is a noticeable improvement over the stock spring kit.
The recoilless charging handle and buffer are two items that I would recommend for everyone. You can install both in less than a minute and they make a world of difference for getting back on target quickly. Ok guys, enough of my rambling. I just wanted to share my impression of the upgrades I installed. Definitely worth the time and money in my opinion.


Just got my trigger bundle i ordered very fast shipping great customer service thanks mcarbo. Im goin to order the stainless feed ramp before i install trigger kit so there will be only one teardown i also plan to hydro dip in a blue/black digital while i have gun tore down there will be pics and review once all is done and back together


Just installed the mcarbo brake. Decided to ditch the jam nut as it only allowed the brake to thread on a few turns. Used some brake shims and some rocksett. Came out perfect.


Yes I too Abort’d the Jam Nut Idea and went with a AR shim Kit from Joe Bob’s Outfitters!
The Timing would not line up for me with it.


Just wanted to “Thank You” and your company for making quality upgrades for the S2K. I bought the S2K to carry as a companion to my Glock in my GHB. When I first shot the stock S2K I was extremely disappointed. The accuracy was there but the trigger sucked and felt cheesy and sight acquisition was slow.
I learned about your company searching for replacement trigger components. I ended up purchasing the complete trigger kit, trigger bar, SS feed ramp and polishing kit, tube cover, recoil donut, and rear sight. WOW! What a difference. It has a much more solid feel on lock up, a lighter, crisper trigger with much less slop, and quicker target acquistion with the new rear sight. After 100’s if not 1000’s of rounds with these upgrades, with zero failures, the S2K is a blast to shoot and 100% reliable.
Once again, thanks for the making quality parts that took my S2K from a firearm I was regretting buying to one that I now truly enjoy owning.


Just installed the Trigger kit and SS feed ramp, now the trigger break is rather high, I don’t have a trigger pound gauge but I have others to compare it to.

It is a smooth trigger with the safety on, no binding, but with the safety off when you come up the the break, it takes quite a bit to break.

I took it back apart this morning and everything looks like it is where it should be.



Ordered all the goodies for the s2k from mcarbo. Just waiting for them to arrive. Only thing left is a qd red dot mount and a holosun green dot (love it on my scorpion).