[Dennishp]

Hopefully someone can help me get a true co-witness with my Walther/Umarex MP5 A5 .22LR

Picked up the MP5 A5 as a plinker w/ a red-dot. Bought a micro dot Aimpoint style clone and a claw rail and cannot get a co-witness sight picture. When looking through the rear aperture and the red dot glass, all I get is the top half circle of the front sight assembly. No front post is visible and I can just barely pick up a red shadow where the red dot is sitting just out of view.

If I do not use the rear sight aperture (just look through the red dot), The dot sits nearly on the top of the front sight protective circle. I'm not prepared to cut the top half of the circle away so the dot is in the clear.

The sight needs to come down a bit get a 1/3 co-witness or even a bit more for a true co-witness.

I know guys here that have the HK MP5 are running the Aimpoint Micro dots w/ the B & T 10266 mount and get a true co-witness.
Mount https://www.hkparts.net/shop/pc/B-T-HK-MP5-MP5K-Low-Mount-For-T1-H1-T2-Aimpoint-91p16862.htm

A few of these same people have the Walther Umarex as plinker w/ other less costly red dot and rails. Usually the Classic Army rail and a Primary Arms Red Dot and claim to get a true co-witness with the iron sights.

My question is..will the more expensive B & T 10266 rail fit on the Walther Umarex MP5 A5 22LR??

I'm hoping a member that owns both will do a test fitting so I'll know before I order the B&T 10266 that it will fit mine. I don't mind spending the money for a rail if I'm sure the red dot will co-witness.

Thanks to any who answer and especially to those who take the time to do a test fitting of the B & T mount on their Walther/Umarex MP5 A5 .22LR

Cheers

 

[bls72bmw]

Great thread, following with interest. Especially regarding the lesser priced optics for my uses.

 

[Pentico'sClone]

Just FYI, if you can get a low enough mount to fit.... a Bushnell TRS-25 red dot will co-witness.

They are cheap yet perform very well.

 

[Dennishp]

I actually have this one:

https://www.hkparts.net/shop/pc/Low-Profile-Red-Dot-Micro-Sight-On-Sale-342p16209.htm

Amazon for $25 and looks to be pretty much a clone to the Bushnell and the Aimpoint size wise.

Rail shown doesn't allow co-witness. Shown here for thickness of the mount and rail. Puts the dot just out of my rear sight.

 

[Anopstyx]

There is also a clone b&t mount made by kley-zion. Is identical except for finish. Less costly and works very well. I don't have a 22 to fit it on though.... Co witnesses perfect with aim point style red dots

 

[fullmann]

The kley-Zion mount will get you a Co-witness with a trs25 (or like) red dot.

https://www.botach.com/kley-zion-hk-mp5-ultra-low-profile-aimpoint-mount/

 

[Dennishp]

Yes, I've seen the Kley-Zion rail and it looks identical to the B & T (which does co-witness w/ the Micro dot on the HK MP 5). Either one would be acceptable but was told that the B & T may not fit the Walther MP5 A5 (so assume the Kley-Zion may not either as they appear to nearly idential).

I've compared pix of the HK MP5 and the Walther .22L and the receiver configuration appears to be the same (of course there is only so much you can tell w/ a picture. If the HK is just 1mm narrower those rails won't fit the Walther.

HK Parts sells other rails made for the Walther MP5 and are advertised as the Lowest profile available. But unless I see Co-witness in the description, the low profile designation is arbitrary. The B & T does say Co-witness, the other low profile only says you can use your iron sights with the rail installed. (which to me means w/o a sight installed, the rail doesn't obscure the iron sights.

I know a couple of guys have both the HK MP5 9MM (w/ the B&T) and the Walther MP5 .22LR with another cheaper rail and red dots sights. Really hoping one of them finds it in their heart to swap the B&T over to the Walther to check for proper fitment.

As an aside, I was told that MFI is releasing a new low profile rail that is supposed to fit the Walther and co-witness with the irons. I suppose I can wait and see, but really would like to finish the gun project up so I can start burning some ammo.

 

[Dennishp]

So, I broke down and bought the NcStar red dot for the MP5.
https://www.amazon.com/NcStar-1X20-Sight-Mount-DMP5/dp/B000SL11QI

If you look at the front lens of the NcStar, you'll notice almost no extra material between the front scope ring where it meets the receiver.

Really do not like the look, but it co-witnesses perfectly. I was looking to see how low the NcStar sits on the receiver and the lens ring basically rest on the top of the receiver. That being the case, I'm not sure how I can mount a rail (regardless of how low of a profile it is) and then put a sight on it and get a co-witness.

Between the rail thickness and the red dot base material thickness, the red dot will appear to always be just about 1/4 inch too high. The way a rail and red dot may work, the tapered edge of the picattiney rail (tapered edge running the length of the rail that the red dot claw grabs) has to be almost even with the top of the receiver when the rail is mounted. The thickness of the center part of the rail has to be milled down quite thin to achieve that fit.

I have the rail that doesn't work, so I may get my dremel out and start to cut out the underside of the rail to get a lower fit. If it doesn't work, I'm not out anything as the rail I have is pretty much worthless for my needs.

 

[Pentico'sClone]

I have had nothing but grief from NcStar products.

I wish you the best in getting your set up to work.

Personally I never did find a claw mount that fit my MKE 9mm clone just right, or that would hold zero after I removed it for cleaning.
I even did a similar "cutting of material" on the mount to get it to sit lower.

Eventually I had a rail welded to the top of my weapon.
Solved ALL of the problems.

 

[Dennishp]

I was told by Adam at HK Parts that LMT has a new rail coming out this month or next that will fit my rifle and will co-witness w/ a Mico Red dot. I'm really interested in seeing how it's designed to over come the low iron sights. If they can build one, I'll buy it. Only stipulation is it having to be a true co-witness.

I really don't mind losing zero on a red dot if I remove it as long as I have it co-witnessed. Easy to get the dot back on the front post, An un-co-witnessed red dot on the other hand would be a PITA.

I thought about having the receiver drilled and tapped by a gunsmith and add a thin rail to it.