M*CARBO Brotherhood

Tips & Tricks For S2k


@JoeFridaySays I checked mine and it is between 5/32 and 11/64. I must have used a lettered bit when I drilled it.
My sight is like your replacement on the right. It has the same rough flash and it also had flash on the inside before i drilled it out.
The other day, when you said you were going to fill and notch one, it got me thinking.
Is there enough adjustment on the front pin to put a notch on the very top of the sight? Or maybe a narrow slot all the way through the top and then sight it where the pin fills the slot.
I haven’t had time to look about that yet. maybe later tonight i will throw a bore sight on and see what it looks like.


I think there is because the MCarbo rear sight is .060" taller than the OEM sight yet MCarbo says it only requires a “minor” height adjustment and is well within the operating range of the front sight.
If it is a problem, you can get a taller front sight pin for a reasonable price.


what i was thinking too. I had considered something along the line of filling and notching the sight same as you. But i hadn’t thought about just notching the very top of the sight itself until someone had mentioned the taller mcarbo sight. Then the idea clicked.


Let me know what your bore sight test suggests.


yes, I will. I’m going to work on that later tonight and see what I come up with.
I will try to get some results from 25 to 100 yards and see what it tells us.


Here is the filled sight and what I plan for the notch. I have drawn the notch on the target side so you and Jeffing65 can see the relationship to the through and through sight aperture hole and why the fill material is so important. If I can find the time I will cut the notch tomorrow and see if the fill holds up.


OK, here’s the final result and a walk through of the project. The first picture is the sight with the aperture and aperture well filled in with a two part epoxy acrylic.


This next pic is the sight mounted in a jig and marked for cutting which was done with a rotary tool and three cut off discs stacked like a dado cutter.


This is the sight after the initial cut was cleaned up with small hobby files. The plan was to leave the upper portion of the original sight that encircles the aperture for strength. You can see that still remaining in the photo from the target sight side. The problem is that leaves the notch pretty shallow. Making it any deeper, however, would remove that encirclement and cut into the epoxy fill leaving the fill unsupported on one side. I ultimately decided to do that and make the notch deeper.


This pic shows the finished sight with the fill material painted black. (The paint really brings out all the imperfections in the molded plastic!). Note I did not add the planned bevels to the edge of the notch cutout. Because the top of the sight is rounded and not square, the “wings” framing the notch are fairly thin and I was hesitant to make them appear even thinner by cutting a bezel.

Total cost: $5.00 plus shipping for the part, some two-part epoxy acrylic most of which is still available for other projects, leftover black paint, some good conversations on this forum, and the challenge of doing it.

Front Sight Post Upgrade
Front Sight Post Upgrade

Wow @JoeFridaySays very inventive! Good workmanship, looks pro👍


Thanks and looking forward to seeing you as a Moderator. I’ve only been here a short time but you’ve got to earn respect to be entrusted with that kind of position, so congrats.


@JoeFridaySays Please give us a report on how it is in use. It looks great.


Will do. It may be a bit before I can get to the range though. Work commitments. I’ll see if my son wants to take it. He’s a better shot now anyway. :slightly_frowning_face:


A FINAL NOTE: You do not need hobbyist files. When I realized how close the edge width of a standard hardware shop file was to my planned notch size, I threw the plan out the window and let that dimension define the width of the notch. Besides, it cut far more efficiently than those dainty hobby files. :sweat_smile:


Almost gave me a heart attack

Tonight after cleaning my Sub 2000, the bolt would not slide back in. I had read on the Forum that this was fairly common and that you need to be aggressive in encouraging the bolt to ride over the hammer and find its way home. What the posters failed to mention was that when the bolt eventually does break free in response to that aggression, it does so with a vengeance, slamming home with a noise that sounds with absolute certainty as if you have completely destroyed the firearm. Fortunately, all was well and my heart rate is slowly returning to normal. Anyway, thanks for the tip…I think. :confused:


it was a good thing i read about the issue of bolt insertion before i cleaned my s2k the first time (i always clean any new weapon out of the box)…

fortunately i have some carpeting at the workbench and merely gave the carbine a light tap muzzle down, and the bolt assembly slide home, most likely on its own inertia

my biggest fear is encountering the dreaded ‘raid the kitchen drawer for a long-handle wooden spoon’ instance, where one inadvertently pulls the trigger with the safety off and while the bolt assembly is out of the carbine


on the ‘all thumbs, no brain’ Gulf of Mexico


It had never been a problem before, and it yielded to a hard smack this time. It just seemed louder than the normal bolt slamming home; probably because I wasn’t expecting it. I don’t see how it actually could be louder.

I already had a dowel ready and waiting though - just in case.


@linux_author, of all the indignities I’ve suffered trying to get my S2k going, I’m happy to say at least THAT particular one hasn’t occurred. Mainly cos I’d read about it here first👍


12g brush and cleaner works nice down the tube


tks! i’m giving you a big thumbs up on this one - i was just positing the issue of bolt tube cleaning this morning… sheesh!


on the ‘slow on the trigger’ Gulf of Mexico


I use a 12ga bore snake. :+1:


I just stripped mine down again after previous post about bolt not sliding out. S2k gen2 bolt wont slide out of tube
I ran 30 rounds through it this morning after the previous reassembly, then broke it down.
I had to lightly tap it out part way. It was rubbing on ridges at the edge of the mushroomed area.
I filed the ridges smooth with the tube and very lightly polished it along with the bolt using a fine piece of emery cloth.
Now with just a tip it smoothly slides out into my hand. It will drop in and stop where the charging handle can be slid in.
It then easily goes all the way forward with just a little push.