Holosun EPS & EPS Carry - Enclosed 407K/507K

[GJM]

Outside my lane:

Based on my discussion with a 1100+ person police dept armorer, I almost wonder if taking 3 threads off and/or tapering the extractor side screw should be a starting point of certain screws as a best practice?

CHPWS provides different screw lengths for Holosun vs the RMR/SRO (which requires longer screws). Also, Holosun provides two length screws with most of their optics. With the 365, I don't believe the optic screw can interfere, because of a different design than the Glock.

[Palmguy]

When I installed a 6 moa EPS Carry on my wife's Spectre Comp tonight, I needed a lot of left correction in windage to get the dot close to the iron sights. In my experience that is unusual with Holosun optics, which are usually pretty close to zero. YVK, I believe, encountered something similar with his install on a 365X slide. Neither of those pistols has a plate.

Good looking optic.

I just installed a 407K and a 507K on 365XLs and both displayed the same behavior.

[HCM]

When I installed a 6 moa EPS Carry on my wife's Spectre Comp tonight, I needed a lot of left correction in windage to get the dot close to the iron sights. In my experience that is unusual with Holosun optics, which are usually pretty close to zero. YVK, I believe, encountered something similar with his install on a 365X slide. Neither of those pistols has a plate.

Good looking optic.

I just installed a 407K and a 507K on 365XLs and both displayed the same behavior.

I had a similar experience when I put a 407K on my SIG P322. Needed so much windage it ran out just before achieving zero.

figured out the optic was mounted with a slight cant. Re-mounted the sight (straight this time) and zeroing consisted of undoing the prior windage correction. I.e. it would have been dead on if mounted straight in the first place.

Have not experienced that can’t issue with Romeo Zeros on P365XLs.

[JCN]

figured out the optic was mounted with a slight cant. Re-mounted the sight (straight this time) and zeroing consisted of undoing the prior windage correction. I.e. it would have been dead on if mounted straight in the first place.

Have not experienced that can’t issue with Romeo Zeros on P365XLs.

This has been my experience with mounting optics as well.

It’s kind of like installing Glock front sights. If you don’t pay attention and try to keep it from rotating when you twist the screw… the optic twists too.

So you have to really hold it centered when you install the mounting screws.

[JCN]

@HCM
@YVK
@GJM

I think the difference between slides and optics exhibiting free twist partially depends on:

The front/rear cut of the slide: the different K mounting pattern optics from different companies have slightly different front to back dimensions so some of the generic cuts aren’t as tight and allow twisting.

The front mounting bosses: the different brands have different boss depth so cuts now have either no bosses or smaller bosses.

Those bosses are what help resist twisting of the optic on installation.

So careful attention to optic twisting should be paid if there aren’t bosses, are tiny bosses or loose boss cuts.

[DpdG]

FWIW (and the locktite is still drying so no live fire yet) The unit I put on a G43x MOS aligned with the factory plastic sights without any adjustment. I did have to tap the shim down onto the slide bosses to seat it fully.

[David S.]

I really hope they can design one to fit the full size RMR/507c footprint.

[JCN]

I really hope they can design one to fit the full size RMR/507c footprint.

Hole spacing wise, the K screw holes are the same distance as the DPP and Romeo1…

The reason I mention that is on the 320 optics slides they have dual hole patterns for RMR and R1…

Which means you could probably have K screw holes made in an RMR cut slide to run an EPS…

[davisj]

@JCN, to clarify, are you saying a Holosun K or EPS will mount directly to a 320 slide? I have a 320X Compact slide with optics cut (older design, not the Pro cut) that needs a dot. I’ve been hesitant to get a Romeo 1 Pro and if the K mounting footprint will fit I may get an EPS for it.

Thanks!

[JCN]

@JCN, to clarify, are you saying a Holosun K or EPS will mount directly to a 320 slide? I have a 320X Compact slide with optics cut (older design, not the Pro cut) that needs a dot. I’ve been hesitant to get a Romeo 1 Pro and if the K mounting footprint will fit I may get an EPS for it.

Thanks!

Can you take a picture of your cut? If there are no nubs then I think yes but you might want to confirm by measuring hole spacing with a caliper. There will be a gap though if it bothers you cosmetically.



This is an RMSx on a slide cut for a DPP.