HKPRO Forums banner

1 - 20 of 35 Posts

·
Registered
Joined
·
289 Posts
Discussion Starter · #1 · (Edited)
Here is my attempt to gather all the information on MP5 Red Dots and Mounts. I have threatened to make a one stop thread and here I am! Since I got the MP5 bug I found myself searching for this info. Then once I had a few mounts/optics under my belt I would comment here on Pro or Arfcom. The same questions always seem to come up so maybe we can get them all answered here.

Coming from the AR platform there is a standard of absolute co-witness and 1/3 co-witness. There is no such standard with the MP5 but I will try to relate my findings to these standards.

Absolute co-witness means that if you are perfectly aligned with your optic, the irons are also lined up in the center of the optic. Any other setup, means the irons are either above or below the red dot, or not in the view at all.

If the irons can still be seen through the optic you can get a co-witness when you go off axis on the red dot and use the "parallax free" ability touted by manufacturers. I use parenthesis because it has been shown that most, if not all, red dots have parallax the further you get from the center of the optic. Green Eye Tactical did some good work on this topic:
https://www.greeneyetactical.com/2017/07/27/comparative-study-of-red-dot-sight-parallax/


I do not have the basic irons height above bore numbers for the MP5. I gathered data from manufacturers where I could with respect to optical height for their mounts and these are the numbers I discuss below.

My own MP5 experience is this: I own a Z-5P (MP5K-PDW) that came with an optic rail. I have owned the B&T 10266 & 21241 and the MFI Low Mount. EDIT: I have a fullsize AT94P now as well. But of course this all applies to both models. On the fullsize I am using the 21241 and Holosun micro.

Absolute Co-Witness
Battle Steel direct mount. This *looks* really low and could be absolute co-witness. I have never seen one in real life but I did test the MRO mount further down this post. ***Confirmed by user Dragnet, this is absolute co-witness***



RMR direct mount to rear sight. This option replaces the rear sight with a mount designed for the RMR. Yup, this can't be called co-witness since there is no rear sight. How about this is "absolute co-witness" height.

Pics from Oicani.









How to get close to 1/3 Co-Witness

The lowest MP5 adapter rails I know about are the B&T 10266 (short) and the B&T 21241 (long). MFI has something called the Ultra Low and I believe these are as low as the B&T. I also believe the welded on rails are about the same height as these rails but cannot confirm that.

Mount/Optic Combo
Aimpoint Micro factory H1/T1 mount, non-QD - 18mm (~0.71") optical height
+
Aimpoint Micro H1/T1 or clones like the Holosun/PA.
=
~1/3 Co-Witness, I suppose the red dot is about halfway between the front sight and the bottom of the front sight hood.

NOTE: You can buy a QD upgrade/latch for those mounts. Botach sells a kit as well.

B&T 21241 + Holosun + Aimpoint Low Mount (non-QD)



If you use the Aimpoint LRP QD without a spacer, the dot is closer to the hood. This mount is rated at 20mm which is 2mm higher than the original low mount. It makes a difference! I have one of these and learned the hard way that it was higher than the non-QD.


Next up are the Aimpoint 30mm Optics with a Low Ring (21mm optical height per Vortex and Aimpoint). This is pretty close to the hood and I can see why guys cut off the hood with these setups.

Shown below is the PA 30mm Clone in a Vortex Low Ring:




From user CZ-75:





A new option the direct mounts from Battle Steel (aka Botach). This MRO on the direct mount is about the same height as the 30mm Optic and Low Ring above.





Shown below is the PA 30mm Clone in a Vortex Low Ring BUT with the Zenith Rail, which put the dot above and clear of the sight hood. Very usable with decent cheek weld. NO co-witness as shown below.



EDIT: I removed my conclusions. Leaving this thread purely just information.


MRO on Trijicon factory low mount 25mm or 0.985" optical height.

On the low rails 10266/21241 this puts the dot on the hood. On the supplied Zenith Rail, which I *think* is the same height as the SP5K rail, the dot clears the hood. I used this initially and it worked great.





More to follow:
- Fast Fire 3 on supplied low mount. No numbers and I remember the dot on the hood with the low rails.
 

·
Registered
Joined
·
289 Posts
Discussion Starter · #2 ·
More on Micro Clones and Mounts

Note that I use Aimpoint mounts only for these clones.

On the left is a Sig Romeo5 + Aimpoint Micro LRP Mount. On the right is a Holosun HS403GL + Aimpoint Low Mount.

Aimpoint states the optical height of the Micro LRP is 20mm. The non-QD Aimpoint Low Mount (newer square version) is 18mm. What I didn't notice in the past is the "body" of the Sig Romeo5 is also higher than the Holosun. I took a measurement when mounted on that rail and the Sig is 3mm higher (so 2mm from the mount and assume 1mm from the body).


 

·
Registered
Joined
·
191 Posts
I have the Battle Steel mount for Micro-style sights and it's perfect. Absolute cowitness, lines up great, very low profile.
 

·
Registered
Joined
·
289 Posts
Discussion Starter · #5 · (Edited)
I have the Battle Steel mount for Micro-style sights and it's perfect. Absolute cowitness, lines up great, very low profile.
Thanks. OP is updated.

Absolute cowitness is a misnomer as there's no rear sight. That said, thanks for the posts and especially pics!
Haha, very true. I made some changes to the OP! Good catch.

Now that that the KAC rail/system is coming online again it would be great to see where both the 30mm and the rail put the optics.

EDIT:
Found this picture but I cannot remember the deal with the Fast Fire 3. Offhand, I want to say it was still not as low as the Micros but obviously its lower than the MRO/Low mount (~25mm). I hate to guess, but I remember the dot being on the hood with that Zenith mount. Not sure where it would be on the 21241/10266. I am using that optic on a pistol but if I get bored I can move it over to the MP5 and see whats what.

 

·
Registered
Joined
·
110 Posts
Here's another mount for the Trijicon RMR which replaces the rear sight that's advertised to give full co-witness. I believe a couple members have this setup. I have an SP5K arriving this week along with an RMR type 2 and the mount I'm describing. Here's a link to the mount that is sold on Gunbroker below. I have no vested interest in the product or seller, just providing a different mount for information's sake.

https://www.gunbroker.com/item/750621194
 

·
Registered
Joined
·
70 Posts

·
Registered
Joined
·
10 Posts
Has anyone imported one of these mounts yet? Anyone stateside offering this mount currently? Very interested in this low profile solution. I believe a Leupold DPP shares the same mounting pattern as the Shield, so this would be a killer setup.
 

·
Registered
Joined
·
158 Posts
Has anyone imported one of these mounts yet? Anyone stateside offering this mount currently? Very interested in this low profile solution. I believe a Leupold DPP shares the same mounting pattern as the Shield, so this would be a killer setup.
I ordered the mount from shield and the SIS from brownells, the mount needed to be filed a tiny bit to fit on the rear lug on my omega clone. absolute co-witness. will be shooting it soon to try it out.
 

·
Registered
Joined
·
20 Posts
Sorry for the low quality pictures in advance, the camera on my phone is low budget as I'm not a huge smart phone user.

Zenith Z-5RS with C-More Systems RTS:

Xv1pMlc.jpg


Down sight view :

Q8trAId.jpg
 

·
Registered
Joined
·
2 Posts
My set up after a lot of research. Think its going to work out great. I can still aim with my irons thru the precision scope mount. Holosun he507c-gr green Dot on a 45 Arisaka offset mount for up close and personal as well as a back up to the Steiner px4i 1-4 which I can still use for cqb and zoom in for positive target id and precision shot if need be. Can't wait to get to the range and try this set up out. My first time posting something online hope it works right, if not my apologies in advance.
 

Attachments

1 - 20 of 35 Posts
Top