I haven't bought the 507K yet, but I do have the 507C. It came with everything I needed to install and adjust, including the screws. I can't imagine the 507K wouldn't come with everything as well.
Yes they are painted on there on the sides of the red dots.
To mount the Holosun HE507K-GR X2 1x Green Dot Reflex Sight to a Springfield Hellcat OSP, you will need to use the C&H Precision Weapons Springfield Hellcat w/ RMSc Footprint Adapter Plate, which converts you RMSc optic cut to the Holosun K cut. The adapter can be found by using the link below:
https://www.opticsplanet.com/c-h-precision-weapons-springfield-hellcat-w-rmsc-footprint-adapter-plate.html?_iv_code=5HT-RMT-CHSHR-SAHC-HOLOK
The hardware provided with the Holosun HE507K-GR X2 1x Green Dot Reflex Sight will be compatible with your S&W Equalizer as it directly fits to the optic cut on your slide. No additional or supplemental hardware would be required.
Yes, the Holosun HE507K-GR X2 Green Dot Reflex Sight will mount directly to the optic cut slide on the S&W Equalizer without the need for an adapter plate.
To fit the Holosun 407K to a C.O.R.E. model M&P, you would need to use an adapter plate by CHPWS that converts your optic cut to the 407K footprint. With that plate, you can fit this Holosun 407K as well as the Holosun 507K.
The Mossberg 940 Pro Tactical has a receiver mounting slot for red dots that have the Shield RMSc footprint. The Holosun HE507K-GR X2 Red Dot Reflex Sight uses a slightly modified Shield RMSc footprint so it may fit the optics mount on that shotgun but slight modification may be needed to fit properly.
No it won't. It would need shield/DDP footprint cut mount or slide.
The Holosun HE507K-GR does not include a picatinny adapter. It was designed to mount to slimline pistols. It can be mounted to a picatinny rail with the use of a picatinny mount, however, as this is a smaller optic with a proprietary footprint, modification to the mount may be required. RMSc pattern mounts will work but you will need to remove the rear recoil lugs and shorten the front two. Universal mounts such as the SIG SAUER Universal Reflex Sight Riser Mount (linked below) will work and will not require modification.
https://www.opticsplanet.com/sig-sauer-universal-reflex-sight-riser-mounts.html
The Holosun HE507K-GR X2 will mount directly to the optic ready slide of the P322 without the need for an adapter plate. To mount this optic to your P229, you would need to use the Evolution Gun Works Leupold DeltaPoint Pro Sight Mount and modify the plate by removing the rear recoil lugs and shortening the front two. Once modified, you will be able to install this optic. The adapter plate for the P229 can be found linked below:
https://www.opticsplanet.com/evolution-gun-works-leupold-deltapoint-pro-sight-mount-for-sig-sauer-p220-p226-p.html