M*CARBO Brotherhood

Guide To A Perfect Sub2k Detailed Summary

First, this will be a long post for those who don’t like reading short stories, sorry. I thought this might be useful to others who are on a similar Sub2K perfection journey and may benefit from this to save themselves some time and energy. (This starts slow but picks up quickly and I have pictures :grinning: ) Second, this is everything I have learned from doing the all in one trigger job, other improvements, accessories, and from various posts around the forum. I hope collecting all of this scattered knowledge into a single source will be useful to someone. I wish to give credit to those who have shared their wisdom, knowledge, experience, and fellowship. So as not to have too many breaks in the flow of the text thank you in advance to, in no particular order: @Kona @Dred @Turmeric @dave67 @Johnksg @Flogrown @Wedge @Boomchucker @TriggerHappy and of course, Thank you @ChrisNelson
I love rifles but have a serious shoulder issue. I, of course, have an air rifle. Also a Kel-Tec CMR30 as the recoil on it is negligible. Shotgun is out of the question after 2 shots I am done and seeking Advil. I can’t 5.56 nor 7.62. My hope was a PCC would be able to give me the PDW I want without the recoil that would take away the joy of using it.
I picked up my Sub2K October 10th. Immediately field striped it and gave it a good lubrication. Took it to the range and got it properly sighted for 25 yards put about 200 rounds through it. There was more recoil than I had hoped. While searching for a recoil buffer I came across MCarbo, joined the Brotherhood on the 11th, and the rest is downhill from there. Here is the brief history and process to the perfect Sub2K.
Task #1: Recoil mitigation. Step 1 - Recoil buffer “Red lifesaver” ($10) so I can still lock the bolt back, unlike the Tacticool buffer. Recoilless Charging Handle ($30), both seemed cost effective and easy. After testing, not enough. Step 2 – Muzzle Brake ($65) and Heavy Bolt ($45) (forum confirmed Sub2K still cycles reliably with RCH & Heavy bolt) tested, very nice. But when folded, ends look uneven and wonky. Step 3 - Time for a bolt tube cover ($15) and recoil pad ($25). ATI is not the choice for me as I have heard too many bad things about it splitting from repeated ON/OFF. Also not a fan of the way it looks. Adapting for an AR-15 butt stock requires a bit too much custom armorer effort for this guy. I chose the easy and awesome Adaptive Tactical EX Performance Recoil pad. Looks great feels even better. To mount, drill a small pilot hole and use (2) #8 ½” wood screws.
Now she feels like a 22LR. My range routine is to shoot 3 shots in 2 seconds at 25 yards from a low ready start. My groups are much improved as well. What was 8-10” groups are now 4-5” (also due to improving the sights, Task #2).


Because a post limits one to mentioning more than 10 users continued from post #1 Thank you, @Scooter @GinNC @JoeFridaySays
Task #2: Improve the sights. Step 1 – Cost effective and quality red dot TRUGLO 2X42mm ($40). Even with 2X magnification I can still keep both eyes open to comfortably acquire the target easily. I tried a ½” riser quick disconnect but it was too tall to nicely co-witness even with the flip down rear sight. So I ended up going with Tuff brand ¼” Cantilever rail ($15) with 2 knurled finger nuts. Brings optic closer for better eye relief and even easier target acquisition. Plus MCarbo Flip down rear sight ($65) for co-witness in the bottom 1/3 of the aperture, perfect. Back up iron sights when you need them, folded away when you don’t. Originally ordered the notch sight to be similar to my pistols, but without dots, my POI elevation was not consistent. So the wonderful Jacqueline in MCarbo customer service exchanged for the Peep without question or hassle. The Picatinny rail on the Sub2K is not flat. Using 2X4s and a speed square to ensure true 90deg, use a ‘bastard’ file to remove the crown on the rail (a.k.a. forum known as a Wedge Job to eliminate the Wedge wobble). Now the optic will consistently hold the zero each time you reattach the optic. Using Iron sights still needed improvements. Step 2 – Front Sight use AR15xtreme.com ball front sights ($13). Paint the Bead (Nail polish) with white first then a luminescent florescent light green and a THIN THIN clear coat. NOTE: Be somewhere without shag carpet or nooks & crannies that the front post detent pin can get lost in. I guarantee trying to put in the front sight you will have that pin jump out on you and you will have to get out of the chair and crawl around to find it.


Task #3 Improve the trigger: The stock 9.5lb trigger pull was alright for a rifle but I wanted it to be similar to my pistols. So the day it posted on MCarbo, I ordered the All-in-one Pro performance trigger job bundle ($225). Step 1 - If it is your first time diving into the inners, one MUST watch the 50 minute video by @ChrisNelson . There are all sorts of tips and tricks in the video which I found most useful. But, (there is always a but…) be wary of following it to the letter. Step 2 - I did just that and when Chris puts in the extended magazine release he fails to mention transferring the mag catch plate from the original release to the extended. So after reassembling and testing the trigger, great! Test the Mag release and mag just falls right out, $hit, F#ck, D@mn! Don’t make the same mistake I did. Luckily my fingers are long enough I could put the mag catch plate on the extended release through the mag well without having to disassemble.

Step 1A – (Yes, I’m telling you this after Step 2) Prep work. Polish the feed ramp and work on the trigger bar before you open the grip housing. They take about 60-90 minutes combined. I gave the performance trigger bar rounded edges and polished at points where contact is made. Also polish the engagement surfaces of the Sear and Hammer. Lastly the coup de gras, the angled surface of the safety (the safety, sear, and hammer contact/engagement surfaces can only be polished mid job and not as part of the prep work) I hereby dub this process as the “TriggerHappy-Turmeric1 Job”. I do not have a meter but I am certain trigger pull is well below 5lb. It is definitely lighter than my P365 which is a known 5.25lbs, also my PMR30 which is a known 5lbs even.Surfaces%20to%20polish1 P1010342


Task #4 Accessories: Step 1 - I added a Flash Light/Green Laser combo (Chinese 300 lumens for $68 on DHgate). Because it is a well-known fact that in a high-stress quick-react scenario, fine motor skills are null. So the laser is for anything quick and close and the red-dot is for more ‘out there’ targets. Now I am set for anything from 2-50 yards. Step 2 – A grip. This is a very personal subject for many. I can only communicate what I found to be best for me, your results may vary. I didn’t like the feel of the bottom Picatinny rail as I wasn’t certain where my hand was without looking at it. So I bought the MAGPUL XTM hand stop kit so I always knew where my hand was and could therefore always, without looking, turn ON/OFF my light/laser without feeling for it and stop dreaded accidental ONs. It feels pretty good and has a nice sleek look, gives a design that won’t add bulk nor weight. I have an angled foregrip on my CMR30 and have grown to really like it as I have more contact surface of my palm to the firearm. We all know more contact surface means more control. So I relented and bought a good looking low profile angled foregrip for the Sub2K. Step 3 – Case. If you have not visited the page: https://www.mcarbo.com/sub-2000-case.aspx you need to. I settled on a Goplus 18.5” aluminum framed lock box hand gun case for $25 on Amazon. It fits with the muzzle brake and butt stock pad and still ½-¾ inch left on each end. Still fits nicely under the back seat of the SUV.

Now I am just debating whether to disguise making it pink and give it girly girl stickers like @Boomchucker 's Air Force friend with the “pinky purple fairy princess unicorn teddy bear” camo job.


@Gatekeeper a pretty detailed step by step process you are posting brother!

Thank you!

I enjoy the pics and long explanation of your thought process in your set-up. (Not all of us have short attention spans!)

Well done and well written.:+1:


@Gatekeeper Wow Russ, great detailed post and pictures on your S2K build. Very interesting to read and see pictures of another brothers Sub and just keeping an open mind and what their thoughts and ideas are.


Forgot to mention in the accessories, a 32 round magazine “Happy Stick” and ETS Speed loader. Both the stock 17 round magazine and 32 round happy stick fit in the case along the handle side edge. (Not pictured though…)


@Gatekeeper Well done Russ, well done indeed!

Hope to see more write ups like this from you in the future.:grin::+1:


Thanks brother for sharing. Nice write up, thanks for the pics, your knowledge and the shout outs to your fellow M*CARBO members!
:beers: :+1:


@Gatekeeper Thanks for taking the time to do a great write up and great pictures. :+1:


@Gatekeeper well done Russ! Thank you for the references and recognition, this is getting me motivated to pick up where I left off on a new mod for my Sub2k… soon. :wink: :+1:


I read every word. Well done sir, and much appreciated. You’ve got me chomping at the bit to get my hands on mine!

Question … For recoil, what changes produced the greatest reductions? Seems like the buffer and spring were just so so?


@PattonWasRight If the Sub you have coming is a 9mm then you have less recoil to deal with compared to the .40 (I have the .40). I don’t think it’s any one thing that reduces much felt recoil as it is a combination of items. There is the Kel-Tec Heavy Weight Bolt, MCARBO Recoiless Charging Handle, MCARBO Bolt Buffer, MCARBO Muzzle Break and ATI Butt Stock Pad (pad adds 3/4" LOP). I like the muzzle break because it not only helps reduce maybe some felt recoil but mostly helps reduce muzzle rise and some sort of butt stock pad because the S2K butt stock is hard plastic.


Links. Always need some links and pictures of everything! Either way, love the review, always curious how to change things up a bit. Recoil wise, everything makes sense, the pad is nice but seems to make it really thick, Never mentioned if you’re shooting 9 or 40 though which would change the recoil a lot. I feel the real additions here is the front sight and pad. Everything else is Mcarbo standard or a preference (red dot, foregrip, light etc)’

Still, loved it and makes me miss writing reviews on products. Really need to get back into it.


The Muzzle brake was the biggest reduction in recoil.
The heavy bolt is so-so and the recoilless charging handle is so-so. But together combined with the red lifesaver buffer were also very significant.
Even though it is a 9MM. Once I put the Butt stock pad on, it feels like my CMR30 little to no kick and practically no muzzle rise any more. Perfect.


How does things get so dang twisted around? It’s not my case. I commented favorably on it, possibly mentioning its owner might could be ever confused for one’em My Little Brony dudes from the Air Force I read about.:joy:

Besides, I’m more of a Pocoyo kinda guy myself.


@Aravena I provided the manufacturers name so you can Google and maybe find cheaper than what I paid. But here are links to everything not MCarbo.
Kel Tec Heavy Bolt ($45)
TRUGLO 2X42mm Red Dot ($45)
Bead Front Sight ($14)
Butt Stock Recoil Pad ($24)
32 Round Happy Stick ($27)
Good looking angled foregrip ($6)
CREE LED Flashlight Green Laser combo ($68)
Locking Case ($26)


Sorry about that. :rofl: I edited the post.


Oh you don’t have to! We’re havin fun man! Great write up :+1:


@Gatekeeper great job on the write up. I was going to paint my case pink too but after 2-3 sprays I couldn’t do it any more