What Riser Height for 1/3 Co-Witness?

[Scorpio64 5,147]

I've been shopping QD 3 slot risers and they come in a crazy wide variety of heights.  Ya'd think the product descriptions would make it fairly obvious what height suits a particular purpose, but they don't include that tidbit of data.  I have folding front and rear sights (M4gery flattop) and intend to keep them tucked away mostly, but I'd also like the option to flip up that front sight and see what it's like to use the reflex and the front sight simultaneously.

[Krdshrk 3,877]

Uh - what optic are you using and what mount?  It's more of the optic mount for your reflex sight than any riser...

[Scorpio64 5,147]

Uh - what optic are you using and what mount?  It's more of the optic mount for your reflex sight than any riser...

 

Primary Arms low profile reflex.

 

Fits picatinny and weaver rails Not Rated for shotguns or handguns Length 46mm (1.8"), Height 19.3mm  (.76"), Weight 1.9oz.

 

[High Exposure 5,662]

I don't even see that sight listed in their website.

 

Email PA and ask them what footprint it has - RMR, Burris, Leupold, etc.... And then find a lower 1/3 mount for that footprint.

[Scorpio64 5,147]

I don't even see that sight listed in their website.

 

Email PA and ask them what footprint it has - RMR, Burris, Leupold, etc.... And then find a lower 1/3 mount for that footprint.

 

Standard Picatinny mount.

[High Exposure 5,662]

If that optic is like any other MRDS, the Pic mount comes off leaving a flat base with a particular footprint.

 

Not being able to research the sight, I can't tell for sure but that's how the rest of them work.

[High Exposure 5,662]

Ok, a little research shows that this optic will fit on any Fastfire mount:

https://www.amazon.com/gp/aw/d/B00QFTNA6Q?fp=1&pc_redir=T1#productDescription_secondary_view_div_1466438967226

 

My suggestion is American Defense Mounts' excellent AD22-QD mount with the below spacer for lower 1/3 Co-witness of Burris Fastfire MRDS:

 

https://www.americandefensemanufacturing.com/view/product/948/description/

[Scorpio64 5,147]

If that optic is like any other MRDS, the Pic mount comes off leaving a flat base with a particular footprint.

 

Not being able to research the sight, I can't tell for sure but that's how the rest of them work.

 

HE Thanks for researching this.  I heard back from PA and they say the picitinny mount is removable and confirmed the footprint is the same as Burris (Fastfire). They also said I could use a Leapers 0.83" med height picitanny mount as well.  Since the optic is a budget item I want to mount it on a QD riser, yanno, just in case I need to remove it if the optic soils the bed sheets.

[High Exposure 5,662]

The ADM mount is QD as well. Little locking throw lever on the side lets you flip the lever and drop the mount right off the rail.

 

Keep in mind Leapers isn't the best quality. For attaching a flashlight it may be fine, but for an optic, you may want something a little more robust and higher quality to maintain zero.

 

Good luck!

[Scorpio64 5,147]

The ADM mount is QD as well. Little locking throw lever on the side lets you flip the lever and drop the mount right off the rail.

 

Keep in mind Leapers isn't the best quality. For attaching a flashlight it may be fine, but for an optic, you may want something a little more robust and higher quality to maintain zero.

 

Good luck!

 

To be perfectly honest, I effing hate anything made in china.  I like the American defense mount.  I've been shopping around for the mount and the spacer but cannot seem to find anyone with both in stock.  I may just get the mount and a crappy 3 slot rail for now and grab the spacer when it becomes available.  Also seeing some nice hoods.  I take care of my hardware but a little extra insurance wont hurt.  My brother-in-law elect has a full machine shop.  I may take a crack at making one but the Burris hoods look like they may fit.  I have to see if the openings for the controls are the same.

 

EDIT:  Just found both in stock at SWFA and ordered.  Now the waiting begins.

[High Exposure 5,662]

Awesome!

 

ADM makes great optic mounts. Just remember to use blue Loctite on all the screws when installing the spacer and mounting the optic.

 

Let us see it after you get it all together!

[checko 180]

I'm not a fan of the MRDS types for AR's.  I feel like the window is to small and I dont pick up the dot as quickly.  The PA micro dots are a good option too.  

 

If you want to stick with that setup the ADM mount is definitely a good option.