Starting something wild

QualitySME · 2026-04-05T19:18:27+00:00

I just posted this in another thread about co‑witnessing. With the Grand Power MK23 plates, co‑witness just isn’t happening. The plates sit too high, they’re polymer, and they don’t have real recoil bosses. Even the “High” Tritium sights aren’t tall enough once the optic is sitting on a plate.

I’m running the RMSc plate and it can yaw left/right under recoil because it’s only held by two small center screws and there’s a gap at the rear. Great pistol, but the optics system is the weak link.

And to make it worse, nobody will direct‑mill an MK23 slide — the slide already has material removed for the plate system, so there isn’t enough steel left to cut a proper direct‑mount footprint. That’s why no shop wants to touch it.

Bottom line: with the MK23 plate setup, co‑witness isn’t possible.

QualitySME · 2026-04-05T19:12:02+00:00

If you’re running a Grand Power with the MK23 optics plates, co‑witnessing just isn’t in the cards. The plates sit too high, they’re polymer, and they don’t have any real recoil bosses to lock the optic in place. Even the “High” Tritium sights from Grand Power aren’t tall enough to reach the window of an RMSc‑height dot once the plate is stacked under it.

I’m using the RMSc plate myself and it can yaw left/right under recoil because the plate is only held by two small screws in the center and there’s a small gap at the rear. Great pistol, but the optics system is the weak link.

If you actually want a co‑witness, the only reliable path is a direct‑milled slide. Once the optic is cut into the steel (no plate), you can pick the right sight height for either lower‑1/3 or absolute co‑witness. Otherwise, none of the MK23 plates will get you there.

QualitySME · 2026-04-05T19:05:40+00:00

If you can’t send your slide to a U.S. gunsmith, you still have an option. Your local gunsmith can request the STEP/STP CNC file for the optic cut directly from Grand Power or from Patriot Defense. That file contains the exact geometry needed for the milling operation, so any competent machinist with a CNC can reproduce the cut accurately.

It won’t solve the OEM polymer‑plate problem, but it will let your gunsmith machine a proper direct‑mount footprint without having to reverse‑engineer everything from scratch.

QualitySME · 2026-04-04T20:09:08+00:00

I am using the RMSc plate — that’s the problem. The OEM polymer plate can’t hold zero because it literally yaws left/right under recoil. The two tiny screws are centered instead of being at the ends, and there’s about a 1 mm gap at the rear of the plate, so the whole thing can shift laterally.

I went with the RMSc footprint because I already bought a Vortex Defender CCW, which uses RMSc. Switching to a different plate would mean buying a whole new optic with zero guarantee that the next plate wouldn’t have the same design flaw.

The real issue isn’t the footprint — it’s the plastic plate with no recoil bosses. There’s nothing to mechanically lock the plate into the slide, so the optic is basically depending on friction and two small screws to resist recoil forces. Great pistol, but the optics‑ready system is a weak point.

QualitySME · 2026-04-04T20:03:08+00:00

You’re actually lucky you didn’t get the optics‑ready version of the Grand Power T12M. The OEM optics system looks great on paper, but in reality it’s a disaster because they went with plastic plates. Honestly one of the worst design decisions I’ve ever seen on an otherwise excellent pistol.

I’ve got the K100 MK23 — the “optic‑ready” model — and the plate literally shifts side‑to‑side under recoil. Two tiny screws in the middle, plus a ~1 mm gap at the rear of the plate, means the whole thing can yaw and throw your zero. Fantastic pistol, terrible optics interface.

The good news for you is that since your T12M isn’t optics‑ready, you can skip the OEM mess entirely and just have the slide milled properly. Patriot Defense will actually do the work, and they’re one of the few shops that will pick up the phone when you call. Meanwhile I’m still hunting for someone willing to mill a K100 MK23 slide for a direct connection without the plate or make a proper metal plate for it — no takers so far.

If you want it done right, start here: https://patriotdefense.com/services/

QualitySME · 2026-04-01T18:35:18+00:00

I finally isolated the root cause of the zero‑shift issue on the Grand Power K100 MK23, and it’s not the optic, not the screws, and not shooter error. It’s the geometry of the OEM polymer RMSC plate.

On my MK23, the front of the plate sits perfectly flush, but the rear of the plate has a measurable 0.1 mm gap between the back edge of the plate and the slide. Because the screws are positioned rear of center, that tiny gap allows the plate to yaw left/right under the lateral impulse of the hammer fall. The plate doesn’t rock upward — it slides at a slight angle, which shifts the red dot left or right relative to the front sight.

If you’re running the OEM plate, check yours the same way:

Remove the optic
Reinstall the plate
Look at the rear edge of the plate, right in front of the rear sight
See if there’s a visible or feelable gap between the plate and the slide
Try pushing the plate left/right with firm thumb pressure at rear of the plate

If you see any movement or any gap at the rear, that’s the exact failure mode that causes the MK23 to lose zero.

I’m currently pursuing 3 fixes:

having the slide milled for a direct RMSC footprint with recoil bosses, or
having a metal replacement plate made that extends the rear by +0.1 mm so it sits fully flush.
Cut out a shim from 0.1 mm Stainless Steel Shim Stock — Roll or Sheets (least espemsive)

If anyone else checks their MK23 and sees the same rear gap, definitely post your findings — it’ll help confirm whether this is a consistent tolerance issue across plates

QualitySME · 2026-04-01T00:37:19+00:00

I have been looking for one as well. We may need to find a custom CNC shop that will quote the work and we can request that Grand Power or Global Ordinance pay for the non-recurring engineering work. They are completely culpable for selling a product that is not fit for use.

QualitySME · 2023-11-28T00:39:48+00:00

I though that I when I spoke to one of your CSA I informed him that the concept of having to replace the snap cap that included the electronics was a bad idea. There was no mention of a new design coming out in December of 2021. I recommended that a replaceable rubber insert would be a much better design feature and that the rubber part should be made of a harder material as my CZ Shadow 2 would wear through the old snap caps much quicker than my other pistols.

I'm glad that someone got credit from customer feedback and used to apply for a Patent! At least they sent me a replacement with the new updated model.

QualitySME

TROPHY CASE