What exactly do I need to Mount an Optic

[JamMan1213]

I want to mount the newish Trijicon RMR HD to my Glock 19x MOS slide and to my Staccato HD P4
Do I need a Trijicon sealing plate and a mounting plate?
I've purchased a mounting plate from Staccato for the RMR/SRO/RMRHD and I thought I was buying a mounting plate from the Glock store which turned out to be made of plastic and through a bit of research appears to be a sealing plate because it's so thin and weak that I don't want to use it and not even sure I need it.

So as it stands right now I just bought the OPF-G RMR from Forward Controls for the Glock and as I said, I already have the RMR plate from Staccato.
Do I need anything else besides these two mounting plates or is that it? I'm not even sure why GS would sell me something that is almost as flimsy as cardboard unless it is something that doesn't apply to my needs and is to be used for something else.
Any thoughts on what I'm missing would be very helpful as I'm almost to the point of just taking my pistols to a gunsmith and having him do the mounting.
Anyway, Thanks in advance!

 

[Ron Swanson]

I don’t have an RMR HD but the sealing plate for the regular RMR was because the battery was exposed on the bottom. The HD battery is on top so I would have thought they would enclose it and wouldn’t need a sealing plate.

The forward controls plate is good.

Edit: all you should need is the proper length screws for the optic and plate combination.

 

[Ron Swanson]

Oh there is also this from trijicon’s website.

 

[ShootFirstFirster]

No sealing plate required.

staccato- https://www.riflegear.com/p-24636-staccato-hd-host-optic-mounting-plate-trijicon-srormr-hd.aspx the rmr plate puts you too far forward as compared to this plate MISREAD YOUR POST Thought you had the RMR plate not the SRO/HD plate

Glock. FCD or ARISE

Loctite blue is enough

Torque Wrench.

You should really understand how to do this yourself. If you are in the diamond bar area I can help you.

 

[AR15barrels]

It was mentioned, but the importance might have been glossed over.
The correct length screws.

Q: What exactly IS the correct length?
A: The screw that is as long as possible without being so long as to cause a problem.

There are two possible problems.
1: The screw sticks down and hits something else that's supposed to be able to move.
2: The screw stops at the bottom of the threaded hole and the screw head is NOT holding the optic properly.

The right side RMR screw must not impinge on the extractor depressor plunger on a Glock.
The best way to check for this is to strip the slide down to remove the rear plate, extractor and plunger and then install the plate and look into the extractor plunger hole to see if the screw is sticking down into the hole.
Shorten the screw just enough that it's not sticking down and then reassemble.

To confirm that a screw is not tightening on the bottom of the threads, install the screws without the optic until they are snug.
Now measure how much screw is sticking up out of the slide.
Next, measure how much screw sticks out the bottom of the optic.
Take the overall length of the screw and subtract the length that hangs out of the bottom of the optic and be sure that the amount sticking OUT of the slide is LESS than what's left of the overall screw length after subtracting what hangs out the bottom of the optic.
If the screw is too long, there will be more screw sticking up out of the slide than there is inside the optic when the screw is hanging in the optic.

I do this type of work all the time if anyone finds themselves in need of it.
I also remove broken screws after you break them off or strip them out.

 

[ShootFirstFirster]

It was mentioned, but the importance might have been glossed over.
The correct length screws.

Q: What exactly IS the correct length?
A: The screw that is as long as possible without being so long as to cause a problem.

There are two possible problems.
1: The screw sticks down and hits something else that's supposed to be able to move.
2: The screw stops at the bottom of the threaded hole and the screw head is NOT holding the optic properly.

The right side RMR screw must not impinge on the extractor depressor plunger on a Glock.
The best way to check for this is to strip the slide down to remove the rear plate, extractor and plunger and then install the plate and look into the extractor plunger hole to see if the screw is sticking down into the hole.
Shorten the screw just enough that it's not sticking down and then reassemble.

To confirm that a screw is not tightening on the bottom of the threads, install the screws without the optic until they are snug.
Now measure how much screw is sticking up out of the slide.
Next, measure how much screw sticks out the bottom of the optic.
Take the overall length of the screw and subtract the length that hangs out of the bottom of the optic and be sure that the amount sticking OUT of the slide is LESS than what's left of the overall screw length after subtracting what hangs out the bottom of the optic.
If the screw is too long, there will be more screw sticking up out of the slide than there is inside the optic when the screw is hanging in the optic.

I do this type of work all the time if anyone finds themselves in need of it.
I also remove broken screws after you break them off or strip them out.

He has an 19x MOS gun. His rmr screws are not direct thread. Either way correct screw length applies.

 

[ShootFirstFirster]

I don’t have an RMR HD but the sealing plate for the regular RMR was because the battery was exposed on the bottom. The HD battery is on top so I would have thought they would enclose it and wouldn’t need a sealing plate.

The forward controls plate is good.

Edit: all you should need is the proper length screws for the optic and plate combination.

Also just food for thought. Caveat: I dont buy Chinese made american owned optics but if I did and I also had a glock mos I would run the holosun scs.

Advantage- two visible screws holding optic directly to gun. No screws below deck that are hidden from view, standard height buis. Correct installation of a plate system negates this.


Disadvantage- CHYNA 1/2 kidding. Only green dot as far as I know.

 

[JamMan1213]

You know what? I just found out you can learn a lot by reading the manual that comes with the optic! Haha,
Screw length, sealer plate, needed or not and so forth. Damn, and here I thought they were just killing trees with the making of these silly things called manuals, Thank you guys!