New member with question

All Things SUB-2000!

Greetings everyone! I just joined and awaiting the arrival of my new Kel Tec Sub 2000 gen2 firearm at my FFL. I did a lot of research on upgrades, but when I added the totals up it came to $641! Should my priority be the trigger job kit, recoiless charging handle and recoil buffer? I’m also concerned about placing that new stainless steel part in the recoil spring. I watched the video on YouTube, but seems complicated. Too bad MCABO doesn’t sell the recoil spring with the adapter already installed. :thinking: I look forward to the community’s helpful advice on the upgrade priorities and installing the adapter on the recoil spring.


Welcome to the forum. With upgrades like most of us here have found out can run the overall price of the sub2k way on up there. I will say though the mcarbo upgrades make the sub2k 100% better firearm. My opinion is the stainless steel feed ramp is a must have swap and the trigger bundle kit with aluminum trigger guard. If you plan to mount a optic and want the rifle to still fold the mcarbo mount is great add on. As for the different charging handles and buffer cover i cant say much about these bits cause i didnt see the need in them. Others will chime in soon.


See this thread for how to more easily install the locking pin. The spring acts like a bolt, so after inserting the hex, turn the spring to compress it enough to install the locking pin then reverse the process.
I concur on the stainless feed ramp but you must split the halves to install it. Since putting it back together can be a pain, decide first what you want and do it all in one go.

Just Ordered the New Locking Pin - SUB-2000 - M*CARBO Brotherhood (


Thanks HandyDave, I appreciate your response…


Trigger kit made the biggest difference to me. Just definitely add in the screw kit when you do it because they going to strip. And while you’re in there do the feed ramp and polish everything. I’d recommend doing it in one shot and make sure to take pics as you go.

The buffer tube stuff can be done without opening up the body. If you’re going to break it down in phases do the stuff I said first because, let’s face it, it’s a 9mm. It doesn’t really have a ton of kick in the first place.


@DrWho Welcome to the forum Dan. Most of us oldsters had to split the case many times as Chris kept coming out with new improvements. If I had to do it now I would get the all in one kit.


Thanks, I’ve been wrestling with that. Didn’t realize all the custom upgrades I would need to purchase to improve the firearm. I usually purchase quality firearms that don’t really need internals to improve them (Glocks, CZs, HKs, Beretta, Springfield Armory, S&W). But the reviews on the Kel Tec Sub 2000 gen2 were intriguing and thought I would purchase one. It’s just new to me regarding all the upgrades needed to improve this firearm. Caught me off guard with the pricing. It is what it is…I’ll keep it in my firearms collection safe for a while until I get motivated buying the upgrades I want and getting motivated to tear the sub 2000 apart. Another learning experience in life…always wanted to see what type of gunsmith I would make. :hugs:


Once you upgrade this gun, it is definitely better. But you will never be able to sell it and get what you put into it. My advice is to sell it before you upgrade it. That way it won’t be sitting in your safe only because you put too much money into it(like mine). Hell, even after upgrading the polymer has been known to crack in half while shooting it, and you can’t really upgrade that latching point. Which is really what this firearm needs. People are going to tell you it’s only the colored polymer that cracks, but I’ve seen youtube videos showing otherwise. Stay on the forum because only the best people are here, and Mcarbo parts are definitely worth it. And put that money into a good AR9 if you want a 9mm carbine. But in MY opinion the S2K is honestly a dud.

And let the hate from the members begin.


My personal experience with the S2K is different from many. That may reflect lower expectations or the fact that I am just too cheap to invest everything needed to make this unusual firearm the best it can be. The only internal item I have replaced is the feed ramp because I felt the plastic one would at some point fail. I also replaced the screws and pins at that time.

It may be the thousands of rounds fired, but I find the stock trigger acceptable although it is nowhere near as good as the one on my Canik. I therefore put my money into other things to improve the shooting experience including the revised locking pin, a buttstock pad and buffer sleeve, the two-finger charging handle, the McCarbo optic mount with a Holosun multi-reticle sight, the Red Lion front sight and an angled foregrip.

In retrospect, I should have polished all the internals when I installed the feed ramp but the wear from extensive shooting seems to have smoothed everything out. From my perspective, the mostly external things I did have made the rifle good enough for me and I cannot personally justify the cost of additional internal mods.


If you like to occasionally rapid fire the S2K is actually more fun than an AR by, like, a lot. Especially if you’ve done the right modifications to it.

I, too, have a big “collection” as some might say but unlike collectors I enjoy using mine. You know what I find I usually take to the range? My Sig Cross 308, my Savage A22 Precision, my Sig P320XC and my Kel-tec.

They’re the guns I enjoy the most.

… though, to be fair, my AR is creeping up there too now that I swapped out my trigger for a 2.5 pounder…

Maybe I need to buy another gun case…


Three musts: ditch the plastic trigger, the plastic trigger guard and the baby charging handle.

They feel like crap and diminish shooting enjoyment.

If placing your holes is a priority, addressing the sights is a thing. If your going to put it to work, the optic mount or rear sight can help.

And, near everyone appreciates the bolt tube covered.

Have you considered selling it unfired and ordering the M Series? I am not giving up any of my mods. I installed as they came available and marked a substantial improvement with each.

Stock Sub 2000’s hold value and sell easily.

Link to M Series:


Thanks, Dred…appreciate the input. Just thinking about all these upgrades…ka-Ching, Ka-Ching!


From MCARBO I went with the pro trigger bundle, recoilless charging handle and bolt tube cover. If you ever decide on a recoil pad, Missouri Tactical makes a real nice rubber on that slips on and works great. No dripping like the one offered by MCARBO. I also took a 1/4” drill bit and hand drilled out the rear peep site.

Welcome to the forum!!


Don’t overlook @Dred point about the M-Series. If you can unload the one you bought, purchasing the fully tricked M-Series instead will save you around $200 on the price of upgrades - and you will not have to install them.


That’s always the key…how to sell it and finding a buyer!:thinking: I always get burned selling at a gun shop, but don’t know how to go about selling with the online selling websites. Always easier said than done. I just ordered a lot of the upgrades and will take my time installing in my Armory room. If I get frustrated, I can leave everything on the table and get back to it after I get refreshed! :hugs:


Ok, I just went ALL IN with upgraded parts inside and outside for my new sub 2000 gen2. Wish me luck :four_leaf_clover:! This will be an experience and personal experiment for me (and expensive one), but something I wanted to try. Never did anything like this before…so here goes. Should I complete the internals first with the ramp polishing before or after trigger replacement parts? Than the outside last? Let’s see what kind of gunsmith I am or pretend to be! :roll_eyes:
Carpe Diem,
DrWho (Dan)


Once that baby is cracked open, do everything you can. EVERY internal upgrade on this thing requires you to open the clam shell halves. And once you do, everything goes BOING and your stuck there holding a bunch of parts. So do ALL the internals at once and be done with it. Otherwise you’ll be doing it over, and over, and ove…

You get the point.


@DrWho At the risk of stating the obvious, let me reinforce the BOING mentioned by @Jperr. Work in an uncluttered area and erect some type of sheeting around and over you. The internal parts have a bad habit of launching into deep space or invisible crevices throughout the room causing you to stop in your tracks while you search to no avail and then have to wait for replacement parts to arrive. Other members who have done the full replacement may have tips on a few easily lost items you may want to buy extras of.


Just gonna share my personal, often lonely, opinion. Mirror polishing is more about you than the firearm. I am certain many here have to dim their shop lighting to protect their eyes when splitting their Subs.

Removing metal can damage parts and some corners need to be sharp. I polished enough so that nothing drags on the feed ramp. I stopped long before reflections appeared. I worked my trigger bar and a couple contact surfaces so they don’t drag or grab.

My trigger is as light and crisp as anyone’s. And, iirc, I reported one of the better trigger pulls in this group.

Too much polishing is bad; misplaced polishing is dangerous; less is more. The surfaces that need work actually work themselves in operation at the range.

I haven’t seen anyone admit to going overboard here. But years ago, folks were killing 1911 frames left and right in the name of mirror’d feed ramps. If you own a dremel, don’t use it on your first gunsmithing project.

Brother @turmeric has spent a lot of time sharing his polishing techniques. He is a believer, and I believe his reports are accurate.


I think that is why I have never felt the need for more internal improvements. Back when ammo was less expensive I sent a lot of rounds downrange through my S2K. Now it is mostly my .22s that are getting the range smoothing.