Optics footprints. Confusing as hell, what's the deal?

[kirkland]

Wanting to get a S&W Shield Plus Optics ready which has an RMSc footprint, and mount a Holosun 507k X2 which is also listed as having an RMSc footprint... On some websites... On other sites it's listed as having a "modified RMSc footprint" whatever that means, or a "Holosun K footprint"

I simply can't get reliable info on if the optic will fit this gun or not, it seems like it should be pretty straightforward that an optic with an RMSc footprint should fit a pistol with an RMSc footprint, but I've read reports of people having to modify the slide to get it to fit.

This whole pistol optic footprint thing is about the most confusing thing I've run across lately. What gives? Are most people just running adaptors or is it better to forget the "optics ready" pistols altogether and just get a normal slide cut for your optic of choice?



Edited to add: I've found a little more information in my searching. So there's the RMSc cut, and the K cut which is a modified RMSc cut. Optics with the K footprint like the Holosun will not fit on the RMSc cut. As for S&W pistols, the 9mm Optics Ready Shield Plus comes with the RMSc cut, but the 30 Super Carry Shield Plus comes with the K cut, the 9mm Equalizer also comes with the K cut. The Holosun will mount directly on to both of those pistols, but it will not directly mount on the 9mm Shield Plus. There is no word on if S&W is planning on updating the 9mm Shield plus to have the K cut, several people have written to their customer service department and haven't been able to get a straight answer. However there are 9mm shield slides available from retailers with the K cut.

[gaijin]

From Interweb:
“Holosun 507K is compatible with Shield RMSc/RMS/RMSw/SMS, Sig Romeo Zero Optic, JP Jpoint Optic footprints, cuts, or mounting plates. Guns like the Hellcat, Sig P365XL, and Glock 43X MOS come from the factory ready to receive this optic.
https://culperprecision.com › product”
FWIW

The P365 slide has SIG Romeo footprint. I have 507k on two of them.


And yeah, the whole “footprint” thing can be a ShitShow.

[kirkland]

My initial research led me to believe that that was correct, however, digging deeper, it looks like the Holosun K series will not fit on the RMSc footprint without modification. There's a lot of conflicting information but I found a site that actually had pictures of the two different cuts showing the differences here: https://freedomgorilla.com/blogs/new...rmsc-footprint (I'll try to upload pictures in a bit, phone is being stupid) But some of the S&W compact pistols have switched to the K type cut. They ought to standardize them all to have the same optics cut. I don’t want to use adaptor plates or get the slide machined, or buy aftermarket slides, I'd rather just buy a pistol and put an optic on it.

[titsonritz]

Poke this site for awhile...

https://www.optics-trade.eu/blog/foo...ed-dot-sights/

...still might be confusing but at least it is a road map.

[kirkland]

Poke this site for awhile...

https://www.optics-trade.eu/blog/foo...ed-dot-sights/

...still might be confusing but at least it is a road map.

That is really helpful, thanks. Pretty much exactly what I was looking for. That does confirm my findings about the Holosun K series and Shield RMSc mount.

[georgeib]

That is really helpful, thanks. Pretty much exactly what I was looking for. That does confirm my findings about the Holosun K series and Shield RMSc mount.

Yes, you're correct. A buddy bought a Hellcat, and had to run a file over the posts on the optics cut for the 507k to fit. It was no big deal and took about 3 minutes.

[kirkland]

Thanks guys. Yeah, I'd love to avoid filing on the slide, but if that's what ya gotta do, that's what ya gotta do. I'll probably just hold off on purchasing for a while to see if they update the optic cut.

[Diamondback]

Much as a part of me wants to put an RDS on that 20-year-old 1911 handbuild project, things like this make me wanna just say "suppressor height fiber-optics and be done with it until an Industry Standard format gets established."

[markm]

Much as a part of me wants to put an RDS on that 20-year-old 1911 handbuild project, things like this make me wanna just say "suppressor height fiber-optics and be done with it until an Industry Standard format gets established."

Exactly. My son got a Sig X5 Legion with the fibre optic front sight, and I was just fine with that system.

The horrible and non-standard mounting and fasteners for pistol RDS are a total pain in the ass.

[ViniVidivici]

Yeah, but that FO sucks in low/no light. Just can't compare to the MRDS.

The mounting footprint fiasco is silly though. Just gotta make your choices and deal with it.

I'm alot happier NOW shooting with dots, than I'd be waiting years for footprint standardization.